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1

Thin film superconductor magnetic bearings  

DOEpatents

A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

Weinberger, Bernard R. (Avon, CT)

1995-12-26

2

The formation and analysis of thin film high temperature superconductors  

SciTech Connect

Thin films of high temperature superconductors have been fabricated using a variety of physical vapor deposition techniques. Recent results of HTS thin films produced by coevaporation, sputtering and laser deposition will be briefly reviewed. In addition some examples of the utility of high energy ion backscattering for the analysis of film stoichiometry will be given. 34 refs., 6 figs.

Nastasi, M.; Muenchausen, R.E.; Arendt, P.N.

1989-01-01

3

Thermally induced quasiparticle branch imbalance in thin film superconductors  

Microsoft Academic Search

Thermoelectric effects in superconductors are quite different than in normal metals. One effect is the voltage difference generated between the normal electrons and the superelectrons by a temperature gradient in an electrically isolated thin film of superconductor, the thermally induced quasiparticle branch imbalance. The theoretical background of the effect is investigated, using a two fluid model for the quasiparticle-superelectron system,

P. J. Dolan; P. J. Jr

1984-01-01

4

Fate of the Josephson effect in thin-film superconductors  

NASA Astrophysics Data System (ADS)

The d.c. Josephson effect refers to the dissipationless electrical current-the supercurrent-that can be sustained across a weak link connecting two bulk superconductors. This effect probes the nature of the superconducting state, which depends crucially on spatial dimensionality. For bulk (that is, three-dimensional) superconductors, the superconductivity is most robust and the Josephson effect is sustained even at non-zero temperature. However, in wires and thin films, thermal and quantum fluctuations play a crucial role. In superconducting wires, these effects qualitatively modify the electrical transport across a weak link. Despite several experiments involving weak links between thin-film superconductors, little theoretical attention has been paid to the electrical conduction in such systems. Here, we analyse the case of two superconducting thin films connected by a point contact. Remarkably, the Josephson effect is absent at non-zero temperature. The point-contact resistance is non-zero and varies with temperature in a nearly activated fashion, with a universal energy barrier set by the superfluid stiffness characterizing the films. This behaviour reflects the subtle nature of thin-film superconductors and should be observable in future experiments.

Hermele, Michael; Refael, Gil; Fisher, Matthew P. A.; Goldbart, Paul M.

2005-11-01

5

Thermally induced quasiparticle branch imbalance in thin film superconductors  

SciTech Connect

Thermoelectric effects in superconductors are quite different than in normal metals. One effect is the voltage difference generated between the normal electrons and the superelectrons by a temperature gradient in an electrically isolated thin film of superconductor, the thermally induced quasiparticle branch imbalance. The theoretical background of the effect is investigated, using a two fluid model for the quasiparticle-superelectron system, with attention being given to the question of thermal contract between the sample (thin Sn film) and the (sapphire) substrate. Sample fabrication, using liftoff photolithography to pattern normal metal (Ag) tunnel junction probes (which sample the potential of the quasiparticles) is discussed, as is the experimental apparatus, and the scheme for making measurements using a SQUID picovoltmeter. The thermopower of Sn films in the normal state was measured to be between .19 and 1.4 nV/K, varying with thickness of the film, a value which is considerably smaller than the bulk value of 20 nV/K. An experimental upper bound was placed on the branch imbalance voltage of 10 pV, which gives an upper bound for the thermopower of the normal electrons in the superconductor of 2 nV/K, in agreement with the theory presented.

Dolan, P.J. Jr.

1984-01-01

6

Multiple routes for vortex depinning in amorphous thin film superconductors  

SciTech Connect

ffWe present simulations of vortex dynamics in amorphous two-dimensional thin film superconductors, using a new exact method to evaluate long range interactions between vortices. We find that the onset of vortex motion is dominated by filamentary channels of flow. There are multiple patterns of filamentary flow which are stable in a wide range of bias current. As a consequence, there are multiple steps in the differential resistance, each step corresponding to a different pattern of filamentary flow. This results in a strong history dependence of the depinning current and current voltage characteristics. Our results are in agreement with recent experiments on amorphous Mo{sub 77}Ge{sub 23} thin films.

Groenbech-Jensen, N.; Bishop, A.R.; Dominquez, D.

1996-07-01

7

Vortex Molecules in Thin Films of Layered Superconductors  

NASA Astrophysics Data System (ADS)

In bulk layered superconductors the vortices tilted with respect to the anisotropy axes attract each other at long distance, which leads to the vortex chains structures. In thin film the intervortex interaction is modified by an extremely slow decay of the supercurrent induced by a single vortex line (Pearl's effect). The interplay between these interactions in thin films is responsible for a formation of a minimum of the interaction potential vs. the intervortex distance. This minimum exists only for relatively strong tilting. Depending on the strength and the tilt of the magnetic field we may expect the formation of the vortex molecules rearranging in multiquanta flux lattices. The increase in the field tilting should be accompanied by the series of the phase transitions between the vortex lattices with different number of vortices per unit cell. The Lorentz microscopy technique seems to be an ideal tool to observe such effects.

Buzdin, Alexander I.

2014-01-01

8

Thin film superconductors and process for making same  

DOEpatents

A process for the preparation of oxide superconductors from high-viscosity non-aqueous solution is described. Solutions of lanthanide nitrates, alkaline earth nitrates and copper nitrates in a 1:2:3 stoichiometric ratio, when added to ethylene glycol containing citric acid solutions, have been used to prepare highly viscous non-aqueous solutions of metal mixed nitrates-citrates. Thin films of these compositions are produced when a layer of the viscous solution is formed on a substrate and subjected to thermal decomposition.

Nigrey, P.J.

1988-01-21

9

Discriminator Stabilized Superconductor/Ferroelectric Thin Film Local Oscillator  

NASA Technical Reports Server (NTRS)

A tunable local oscillator with a tunable circuit that includes a resonator and a transistor as an active element for oscillation. Tuning of the circuit is achieved with an externally applied dc bias across coupled lines on the resonator. Preferably the resonator is a high temperature superconductor microstrip ring resonator with integral coupled lines formed over a thin film ferroelectric material. A directional coupler samples the output of the oscillator which is fed into a diplexer for determining whether the oscillator is performing at a desired frequency. The high-pass and lowpass outputs of the diplexer are connected to diodes respectively for inputting the sampled signals into a differential operational amplifier. The amplifier compares the sampled signals and emits an output signal if there is a difference between the resonant and crossover frequencies. Based on the sampled signal, a bias supplied to the ring resonator is either increased or decreased for raising or lowering the resonant frequency by decreasing or increasing, respectively, the dielectric constant of the ferroelectric.

Romanofsky, Robert R. (Inventor); Miranda, Felix A. (Inventor)

2000-01-01

10

Pseudogap in a thin film of a conventional superconductor.  

SciTech Connect

A superconducting state is characterized by the gap in the electronic density of states, which vanishes at the superconducting transition temperature T{sub c}. It was discovered that in high-temperature superconductors, a noticeable depression in the density of states, the pseudogap, still remains even at temperatures above T{sub c}. Here, we show that a pseudogap exists in a conventional superconductor, ultrathin titanium nitride films, over a wide range of temperatures above T{sub c}. Our study reveals that this pseudogap state is induced by superconducting fluctuations and favoured by two-dimensionality and by the proximity to the transition to the insulating state. A general character of the observed phenomenon provides a powerful tool to discriminate between fluctuations as the origin of the pseudogap state and other contributions in the layered high-temperature superconductor compounds.

Sacepe, B.; Chapelier, C.; Baturina, T. I.; Vinokur, V. M.; Baklanov, M. R.; Sanquer, M. (Materials Science Division); (CEA-INAC/UJF-Grenoble); (A.V. Rzhanov Inst. Semiconductor Physics); (IMEC)

2010-12-01

11

Size effect on the thermal conductivity of high-Tc thin-film superconductors  

Microsoft Academic Search

Using the kinetic theory approximation and reported data, this study shows that at low temperatures, the phonon mean free path in polycrystalline ceramic YBa2Cu3O7 can be of the order of the thickness of thin-film superconductors. In this case, boundary scattering reduces the thermal conductivity with decreasing film thickness. A simple method accounts for the size effect on conduction in thin

M. I. Flik; C. L. Tien

1990-01-01

12

Thermal treatment of superconductor thin film of the BSCCO system using domestic microwave oven  

NASA Astrophysics Data System (ADS)

In this work, we report the preparation of a superconductor thin film of the BSCCO system using a good quality powder with nominal composition Bi1.8Pb0.4Sr2CaCu2Ox which was thermally treated using a domestic microwave oven (2.45 GHz, 800 W). This film was grew on a single crystal of LaAlO3 (1 0 0) substrate and exhibited a crystalline structure with the c-axis perpendicular to the plane of the substrate. An onset superconducting transition temperature was measured at 80 K.

Silveira, J. B.; Carvalho, C. L.; Torsoni, G. B.; Aquino, H. A.; Zadorosny, R.

2012-08-01

13

High T(sub c) thin film superconductors: Preparation, patterning and characterization  

NASA Astrophysics Data System (ADS)

A conventional oil-pumped vacuum system equipped with resistively heated tungsten boat sources was used for evaporation of bismuth- or yttrium-based cuprates for high T(sub c) thin film superconductors. A well-ground mixture with atomic proportions of bismuth, SrF2, CaF2 and copper for bismuth-based material, and of YF3, BaF2 and copper for yttrium-based material, was inserted into the boat and then resistively evaporated onto different substrates such as MgO, ZrO2 and SrTiO3 kept at room temperature. Yttrium-based thin films were found to have a better quality upon reduction of fluorine in the constituents. Thus, films prepared with an yttrium BaF2 and copper mixture show a metallic-like behavior, sharper transition and higher zero-resistance temperature as compared with that of films obtained by using a YF2 constiuent instead of yttrium. Bismuth-based thin films were found to lose bismuth during heat treatment unless the copper constiuent ended the evaporation process and was subsequently fully oxidized at 400 C. Bismuth-based patterned films were easily obtained by using a lift-off photolithographic method. Typical thickness of the films was measured to be about 0.5 micron after heat treatment.

Azoulay, J.

14

Thin film growth of the 2122-phase of BCSCO superconductor with high degree of crystalline perfection  

NASA Technical Reports Server (NTRS)

Thin films of the 80 K-phase of BiCaSrCu-oxide superconductor having the composition of Bi2Ca1.05Sr2.1Cu2.19O(x) and high degree of crystalline perfection have been grown on c-axis oriented twin free single crystal substrates of NdGaO3. This has been achieved by carefully establishing the growth conditions of the LPE experiments. The temperature regime of 850 to 830 C and quenching of the specimens on the termination of the growth period are found to be pertinent for the growth of quasi-single crystalline superconducting BCSCO films on NdGaO3 substrates. The TEM analysis reveals a single crystalline nature of these films which exhibit 100 percent reflectivity in infrared regions at liquid nitrogen temperature.

Raina, K. K.; Narayanan, S.; Pandey, R. K.

1992-01-01

15

Shape resonances and shell effects in thin-film multiband superconductors  

NASA Astrophysics Data System (ADS)

We study analytically the evolution of superconductivity in clean quasi-two-dimensional multiband superconductors as the film thickness enters the nanoscale region by mean-field and semiclassical techniques. Tunneling into the substrate and finite lateral size effects, which are important in experiments, are also considered in our model. As a result, it is possible to investigate the interplay between quantum coherence effects, such as shape resonances and shell effects, with the potential to enhance superconductivity, and the multiband structure and the coupling to the substrate that tend to suppress it. The case of magnesium diboride, which is the conventional superconductor with the highest critical temperature, is discussed in detail. Once the effect of the substrate is considered, we still observe quantum size effects such as the oscillation of the critical temperature with the thickness but without a significant enhancement of superconductivity. In thin films with a sufficiently longer superconducting coherence length, it is, however, possible to increase the critical temperature above the bulk limit by tuning the film thickness or lateral size.

Romero-Bermúdez, Aurelio; García-García, Antonio M.

2014-01-01

16

In-situ integrated processing and characterization of thin films of high temperature superconductors, dielectrics and semiconductors by MOCVD  

NASA Technical Reports Server (NTRS)

In this strategy of depositing the basic building blocks of superconductors, semiconductors, and dielectric having common elements, researchers deposited superconducting films of Y-Ba-Cu-O, semiconductor films of Cu2O, and dielectric films of BaF2 and Y2O3 by metal oxide chemical vapor deposition (MOCVD). By switching source materials entering the chamber, and by using direct writting capability, complex device structures like three-terminal hybrid semiconductors/superconductors transistors can be fabricated. The Y-Ba-Cu-O superconducting thin films on BaF2/YSZ substrates show a T(sub c) of 80 K and are textured with most of the grains having their c-axis or a-axis perpendicular to the substrate. Electrical characteristics as well as structural characteristics of superconductors and related materials obtained by x-ray defraction, electron microscopy, and energy dispersive x-ray analysis are discussed.

Singh, R.; Sinha, S.; Hsu, N. J.; Thakur, R. P. S.; Chou, P.; Kumar, A.; Narayan, J.

1990-01-01

17

In-situ integrated processing and characterization of thin films of high temperature superconductors, dielectrics and semiconductors by MOCVD  

NASA Technical Reports Server (NTRS)

In this strategy of depositing the basic building blocks of superconductors, semiconductors, and dielectrics having common elements, researchers deposited superconducting films of Y-Ba-Cu-O, semiconductor films of Cu2O, and dielectric films of BaF2 and Y2O3 by metal oxide chemical vapor deposition (MOCVD). By switching source materials entering the chamber, and by using direct writing capability, complex device structures like three terminal hybrid semiconductor/superconductor transistors can be fabricated. The Y-Ba-Cu-O superconducting thin films on BaF2/YSZ substrates show a T(sub c) of 80 K and are textured with most of the grains having their c-axis or a-axis perpendicular to the substrate. Electrical characteristics as well as structural characteristics of superconductors and related materials obtained by x-ray deffraction, electron microscopy, and energy dispersive x-ray analysis are discussed.

Singh, R.; Sinha, S.; Hsu, N. J.; Thakur, R. P. S.; Chou, P.; Kumar, A.; Narayan, J.

1991-01-01

18

Sputter Deposition of Yttrium-Barium Superconductor and Strontium Titanium Oxide Barrier Layer Thin Films  

NASA Astrophysics Data System (ADS)

The commercial application of superconducting rm YBa_2Cu_3O_{7 -x} thin films requires the development of deposition methods which can be used to reproducibly deposit films with good superconducting properties on insulating and semiconducting substrates. Sputter deposition is the most popular method to fabricate Y-Ba-Cu-O superconductor thin films, but when used in the standard configuration suffers from a deviation between the compositions of the Y-Ba-Cu-O sputter target and deposited films, which is thought to be primarily due to resputtering of the film by negative ions sputtered from the target. In this study, the negative ions were explicitly identified and were found to consist predominantly O^-. The sputter yield of O^- was found to depend on the Ba compound used in the fabrication of Y -Ba-Cu-O targets and was related to the electronegativity difference between the components. An unreacted mixture of rm Y_2O_3, CuO, and BaF_2 was found to have the lowest O^- yield among targets with Y:Ba:Cu = 1:2:3. The high yield of O^- from rm YBa_2Cu_3O _{7-x} was found to depend on the target temperature and be due to the excess oxygen present. The SIMS negative ion data supported the composition data for sputter-deposited Y-Ba-Cu-O films. Targets using BaF _2 were found to improve the Ba deficiency, the run-to-run irreproducibility and the nonuniformity of the film composition typically found in sputtered Y -Ba-Cu-O films. Superconducting Y-Ba-Cu-O films were formed on SrTiO_3 substrates by post-deposition heat treatment of Y-Ba-Cu-O-F films in humid oxygen. The growth of superconducting rm YBa_2Cu_3O_{7-x}, thin films on common substrates such as sapphire or silicon requires the use of a barrier layer to prevent the deleterious interaction which occurs between Y-Ba-Cu-O films and these substrates. Barrier layers of SrTiO_3 were studied and found to exhibit textured growth with a preferred (111) orientation on (100) Si substrates. However, SrTiO_3 was found to be unsuitable as a barrier layer for the growth of rm YBa _2Cu_3O_{7-x}, on Si since Ba reacted with the si after migrating through the SrTiO_3 layer. For sapphire, no textured growth of SrTiO_3 was observed but it was found to be a suitable barrier layer since it prevented any interaction between Y-Ba-Cu-O films and sapphire substrates.

Truman, James Kelly

1992-01-01

19

Peak-effect, a new phenomenon observed at microwave frequencies in high Tc superconductor thin films  

NASA Astrophysics Data System (ADS)

Measurements of microwave surface resistance in magnetic fields (parallel to c-axis), ranging between 0.2 and 0.9 T, of high quality epitaxial DyBa 2Cu 3O 7- y and YBa 2Cu 3O 7- y superconducting thin films show a pronounced peak near the superconducting transition temperature. It is more pronounced at a frequency of 9.55 GHz as compared to 4.88 GHz. The exact nature of the peak is somewhat sample-dependent thereby indicating that the nature and distribution of defects in the films or the pinning sites determine the nature of the peaks; however, it follows the general trend that as the magnetic field is increased the peak shifts towards the lower temperature and is absent when the field is zero. The temperature and field dependence of the peak suggests that this peak could be associated with the order-disorder transition of the flux-line lattice. The peak-effect shows strong frequency dependence close to the depinning frequency of the flux line lattice. We explain our data in terms of the temperature dependence of the Labusch parameter within the collective pinning scenario in type II superconductors.

Bhangale, A. R.; Banerjee, T.; Raychaudhuri, P.; Pai, S. P.; John, J.; Bhagwat, S. S.; Bagwe, V. C.; Shirodkar, V. S.; Pinto, R.

2002-11-01

20

A study of the fabrication and characterisation of high temperature superconductor YBa2Cu3O7 thin films  

Microsoft Academic Search

Thin films of the high temperature superconductor (HTS) YBa2Cu3O7 (Y123) are of great potential in a wide range of applications, including low-loss microwave cavities and filters, bolometers, various superconducting terminal devices, flux transformers, and dc and rf superconducting quantum interference devices (SQUIDs). They also have the potential to give insight into the fundamental mechanisms governing high temperature superconductivity. Y123 coated

Aihua Li

2006-01-01

21

Thin film growth of Fe-based superconductors: from fundamental properties to functional devices. A comparative review  

NASA Astrophysics Data System (ADS)

Fe-based superconductors bridge a gap between MgB2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today's society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation.

Haindl, S.; Kidszun, M.; Oswald, S.; Hess, C.; Büchner, B.; Kölling, S.; Wilde, L.; Thersleff, T.; Yurchenko, V. V.; Jourdan, M.; Hiramatsu, H.; Hosono, H.

2014-04-01

22

Thin film growth of Fe-based superconductors: from fundamental properties to functional devices. A comparative review.  

PubMed

Fe-based superconductors bridge a gap between MgB2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today’s society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation. PMID:24695004

Haindl, S; Kidszun, M; Oswald, S; Hess, C; Buchner, B; Kolling, S; Wilde, L; Thersleff, T; Yurchenko, V V; Jourdan, M; Hiramatsu, H; Hosono, H

2014-04-01

23

Fabrication of high T(sub c) superconductor thin film devices: Center director's discretionary fund  

NASA Technical Reports Server (NTRS)

This report describes a technique for fabricating superconducting weak link devices with micron-sized geometries etched in laser ablated Y1Ba2Cu3O(x) (YBCO) thin films. Careful placement of the weak link over naturally occurring grain boundaries exhibited in some YBCO thin films produces Superconducting Quantum Interference Devices (SQUID's) operating at 77 K.

Sisk, R. C.

1992-01-01

24

Influence of ion irradiated SrTiO/sub 3/ on the properties of thin film oxide superconductors  

SciTech Connect

The quality of high temperature superconducting thin films is dependent on the structure of the substrate used. The present work examines the effects of radiation damaged SrTiO/sub 3/ substrates on the properties of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ thin film superconductors. Prior to film deposition, single crystal SrTiO/sub 3/ substrates were cooled to 77 K and irradiated with 400 keV Ne ions to doses of 1 /times/ 10/sup 15/ and 1 /times/ 10/sup 16/ ions/cm/sup 2/. Following deposition the film/substrate couples were annealed in ''wet'' oxygen at either 850 or 900/degree/C. Films on substrates irradiated at high doses showed an increase in transition width from 2 to 8 degrees and lowered transition temperature from 92 to 65 K relative to films on low dose and unirradiated substrates. These differences are discussed in terms of results obtained from high energy and Rutherford backscattering (RBS) and channeling experiments, scanning electron microscopy (SEM) observations and x-ray diffraction data (XRD).

Bordes, N.; Cohen, M.; Nastasi, M.; Rollett, A.D.; Maggiore, C.J.

1989-01-01

25

Crystal structure, microstructure, surface morphology, and transport properties of Er5Ba7Cu12Oy high-temperature-superconductor thin films  

Microsoft Academic Search

Er5Ba7Cu12Oy is a thin-film high-temperature superconductor (critical transition temperature, Tc=93 K). The crystal structure, microstructure, surface morphology, and transport properties of Er5Ba7Cu12Oy thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), and four-point dc-resistivity measurements under magnetic fields. Oriented Er5Ba7Cu12Oy thin films on cubic ZrO2(100), MgO(100), LaAlO3(100), and SrTiO3(100) substrates were prepared by molecular-beam deposition and post

K. M. Choudhary; P. Seshadri; J. Bae; M. Black; A. Lewicki

1993-01-01

26

Thin film seeds for melt processing textured superconductors for practical applications  

DOEpatents

A method of fabricating bulk superconducting material such as RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} where R is La or Y comprising depositing a thin epitaxially oriented film of Nd or Sm (123) on an oxide substrate is disclosed. The powder oxides of RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} or oxides and/or carbonates of R and Ba and Cu present in mole ratios to form RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}, where R is Y or La are heated, in physical contact with the thin film of Nd or Sm (123) on the oxide substrate to a temperature sufficient to form a liquid phase in the oxide or carbonate mixture while maintaining the thin film solid to grow a large single domain 123 superconducting material. Then the material is cooled. The thin film is between 200 {angstrom} and 2000 {angstrom}. A construction prepared by the method is also disclosed.

Veal, B.W.; Paulikas, A.; Balachandran, U.; Zhong, W.

1999-02-09

27

Thin film seeds for melt processing textured superconductors for practical applications  

DOEpatents

A method of fabricating bulk superconducting material such as RBa.sub.2 Cu.sub.3 O.sub.7-.delta. where R is La or Y comprising depositing a thin epitaxially oriented film of Nd or Sm (123) on an oxide substrate. The powder oxides of RBa.sub.2 Cu.sub.3 O.sub.7-.delta. or oxides and/or carbonates of R and Ba and Cu present in mole ratios to form RBa.sub.2 Cu.sub.3 O.sub.7-.delta., where R is Y or La are heated, in physical contact with the thin film of Nd or Sm (123) on the oxide substrate to a temperature sufficient to form a liquid phase in the oxide or carbonate mixture while maintaining the thin film solid to grow a large single domain 123 superconducting material. Then the material is cooled. The thin film is between 200 .ANG. and 2000 .ANG.. A construction prepared by the method is also disclosed.

Veal, Boyd W. (Downers Grove, IL); Paulikas, Arvydas (Downers Grove, IL); Balachandran, Uthamalingam (Hinsdale, IL); Zhong, Wei (West Lafayette, IN)

1999-01-01

28

Sequentially evaporated thin Y-Ba-Cu-O superconductor films: Composition and processing effects  

NASA Technical Reports Server (NTRS)

Thin films of YBa2Cu3O(7-beta) have been grown by sequential evaporation of Cu, Y, and BaF2 on SrTiO3 and MgO substrates. The onset temperatures were as high as 93 K while T sub c was 85 K. The Ba/Y ratio was varied from 1.9 to 4.0. The Cu/Y ratio was varied from 2.8 to 3.4. The films were then annealed at various times and temperatures. The times ranged from 15 min to 3 hr, while the annealing temperatures used ranged from 850 C to 900 C. A good correlation was found between transition temperature (T sub c) and the annealing conditions; the films annealed at 900 C on SrTiO3 had the best T sub c's. There was a weaker correlation between composition and T sub c. Barium poor films exhibitied semiconducting normal state resistance behavior while barium rich films were metallic. The films were analyzed by resistance versus temperature measurements and scanning electron microscopy. The analysis of the films and the correlations are reported.

Valco, George J.; Rohrer, Norman J.; Warner, Joseph D.; Bhasin, Kul B.

1988-01-01

29

Magnesium diboride: Superior thin films  

Microsoft Academic Search

Conventional superconductors, such as niobium, may soon have competition from a recent upstart. A new technique for growing thin films of MgB2 removes one serious hurdle in the path to commercialization.

John Rowell

2002-01-01

30

Infrared and millimeter wave detection using thin films of Pb doped BiSrCaCuO superconductor  

NASA Astrophysics Data System (ADS)

Thin film detectors made of CuO superconductors were developed in our laboratory. This article reports details of the fabrication and testing of Pb doped BiSrCaCuO detectors. The detector comprises a film sensor housed in a small cryostat with built-in bias supply and temperature control circuitry. The film sensor was first deposited by magnetron rf sputtering and then crystallized under a rapid thermal annealing process. The characteristics of the response of the detector under millimeter wave and infrared illumination were investigated. The millimeter wave response exhibited a Josephson component with a D(*) approximately 10(exp 8) - 10(exp 9) cm.Hz(exp (1/2))/W in the wavelength range of 3 - 8 mm. The transient response to short pulses indicated a time constant tau less than or equal to 10 ns for this component. The response to laser pulses was thermal in origin and inherently compressible, preventing saturation of the detector electronics to intense beams. The wide band characteristic of the responses at both infrared and millimeter wavelengths could be confirmed. The damage threshold of the film sensor was shown to exceed 10 mJ / sq cm per 3 ns pulse. The possible use of these detectors for threat detection and the optimization of their figure of merit are discussed.

Phong, L. Ngo

1995-01-01

31

Spin screening effect in superconductor/ferromagnet thin film heterostructures studied using nuclear magnetic resonance  

NASA Astrophysics Data System (ADS)

Using NMR spectroscopy of the V51 nuclei in the superconducting state of Ni/V/Ni and Pd1-xFex/V/Pd1-xFex trilayers we reported in a recent letter an experimental observation of the spin screening effect [R. I. Salikhov, I. A. Garifullin, N. N. Garif’yanov, L. R. Tagirov, K. Theis-Bröhl, K. Westerholt, and H. Zabel, Phys. Rev. Lett. 102, 087003 (2009)]. This effect, which designates the formation of a spin polarization in the superconducting state, was predicted previously by Bergeret [F. S. Bergeret, A. F. Volkov, and K. B. Efetov, EPL 66, 111 (2004); Phys. Rev. B 69, 174504 (2004)]. Here, we extend our earlier experiments by varying the thickness of the superconducting V layer and by applying the magnetic field not only perpendicular to the film plane as in the previous experiments, but also in the parallel direction. For the latter geometry, which for experimental reasons is difficult to realize, the film is in the vortex-free state. This allows a direct quantitative comparison of the experimental screening effect as derived from a characteristic distortion of the high-field wing of the resonance line in the superconducting state and the theoretical model calculations. We derive a reasonable agreement between theory and experiment, confirming the spin screening effect in the superconductor.

Salikhov, R. I.; Garif'Yanov, N. N.; Garifullin, I. A.; Tagirov, L. R.; Westerholt, K.; Zabel, H.

2009-12-01

32

Thin Films  

NASA Astrophysics Data System (ADS)

Cobalt ferrite thin films are deposited onto quartz glass substrates by chemical spray pyrolysis technique at different substrate temperatures using ferric nitrate and cobalt nitrate as precursors. Thermogravimetric analysis (TGA) study indicates the formation of CoFe2O4 by decomposition of cobalt and ferric nitrates after 800 °C. X-ray diffraction studies reveal that annealed films are polycrystalline in nature and exhibit spinel cubic crystal structure. Crystallite size varies from 39 to 44 nm with the substrate temperatures. Direct optical band gap energy of CoFe2O4 thin films is found to be 2.57 eV. The AFM images show that roughness and grain size of the CoFe2O4 thin film are about 9 and 138 nm, respectively. The measured DC resistivity of the deposited thin films indicates that as temperature increases the resistivity decreases indicating the semiconductor nature of the films. Decrease in dielectric constant (?') and loss tangent (tan?) has been observed with frequency and attains the constant value at higher frequencies. The AC conductivity of cobalt ferrite thin films increases with increase in frequency. Thus, the prepared films show normal dielectric performance of the spinel ferrite thin film. Room-temperature complex impedance spectra show the incomplete semicircles as films exhibit high resistance values at lower frequencies.

Bagade, A. A.; Ganbavle, V. V.; Rajpure, K. Y.

2014-08-01

33

Recent progress on batch processed large size LRE-123 bulk superconductors using a novel thin film Nd-123 seed  

NASA Astrophysics Data System (ADS)

We developed a batch production of large grain c-axis oriented GdBa2Cu3Oy and SmBa2Cu3Oy bulk superconductors by using a cold seeding method in air. Novel thin film Nd-123 seeds grown on MgO crystals were used as a seed crystal for the batch process. Four pieces of single domain Gd-123 samples with 50 mm in diameter were successfully fabricated in single run. Magnetization results confirmed that the samples have a sharp superconducting transition with the onset Tc around 93 K. On the other hand Sm-123 system was studied as a function of varying amounts of BaO2 to reduce the Sm/Ba solid state substation and batch production in air. The magnetization results indicated that superconducting transition was increased with increasing the BaO2 concentration from 91.5 K for 0 wt% to 93 K for 0.2 and 0.3 wt%. Moreover, the maximum trapped field of 2.1 T and 1.5 T at 20 K was recorded 16 mm in diameter Sm-123 with 3 and 1 wt% BaO2 addition.

Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.; Tomita, M.

2013-01-01

34

thin films  

NASA Astrophysics Data System (ADS)

Optical scattering properties of nanostructured matter have crucial impact on performance efficiency of various photonic components, such as waveguides, display elements, and solar cells. In this paper, diffuse transmission properties of nanocrystalline Pb(Zr x Ti1- x )O3 thin films with a high refractive index of ~2.5 and optical transmittance are presented. Thin films with a thicknesses ranging from 50 to 500 nm were studied using integrating sphere technique and results were compared to simulations performed by a scalar scattering theory. Thin films were deposited by pulsed laser deposition at room temperature on MgO(100) substrates and post-annealed at a temperature of 800 °C. Structural phase evolution-induced surface effects, which introduced periodicity on the film surface, cause the definite diffuse elements in transmission spectra of the films. Low and evenly distributed scattering amplitudes in k-space were seen for highly tetragonal- or trigonal-oriented films with non-textured surfaces, which led to low diffuse transmission values ( T D ? 5 %), while confined and increased scattering amplitudes in k-space were seen for tetragonal-trigonal-oriented films, with phase co-existence, which led to microstructure-induced textured surfaces and increased diffuse transmission values ( T D ? 50 %). For highly textured surfaces, scattering amplitudes distributed in tilted ellipsoid shape in k-space was observed. Difference between modeled and measured values was 3.8 % in maximum.

Puustinen, Jarkko; Lappalainen, Jyrki; Hiltunen, Jussi; Hiltunen, Marianne

2014-07-01

35

Thin films  

SciTech Connect

This volume is a compilation of papers presented at the 1990 Spring Meeting of the Materials Research Society in a symposium entitled Thin Films: Stresses and Mechanical Properties II. As indicated by the title, the symposium was the second in a series, the first of which was held at the Fall Meeting in 1988. The importance of thin film mechanical properties is now recognized to the extent that basic characterization techniques such as microindentation and thin film stress measurement are performed routinely, and new characterization techniques are being developed on a daily basis. Many of the papers in the symposium dealt with the developments in these characterization methods and their application to a broad spectrum of materials such as compositionally modulated structures, ion implanted materials, optical coatings, and the numerous metals, ceramics and organics used in semiconductor device manufacture.

Doermer, M.F. (International Business Machines Corp., San Jose, CA (United States)); Oliver, W.C. (Oak Ridge National Lab., TN (United States)); Pharr, G.M.; Brotzen, F.R. (Rice Univ., Houston, TX (United States))

1990-01-01

36

Thin Films  

NASA Astrophysics Data System (ADS)

Effect of annealing temperature on the characteristics of sol-gel-driven Ta ax La(1- a) x O y thin film spin-coated on Si substrate as a high- k gate dielectric was studied. Ta ax La(1- a) x O y thin films with different amounts of a were prepared (as-prepared samples). X-ray diffraction measurements of the as-prepared samples indicated that Ta0.3 x La0.7 x Oy film had an amorphous structure. Therefore, Ta0.3 x La0.7 x O y film was chosen to continue the present studies. The morphology of Ta0.3 x La0.7 x O y films was studied using scanning electron microscopy and atomic force microscopy techniques. The obtained results showed that the size of grain boundaries on Ta0.3 x La0.7 x O y film surfaces was increased with increasing annealing temperature. Electrical and optical characterizations of the as-prepared and annealed films were investigated as a function of annealing temperature using capacitance-voltage ( C- V) and current density-voltage ( J- V) measurements and the Tauc method. The obtained results demonstrated that Ta0.3 x La0.7 x O y films had high dielectric constant (?27), wide band gap (?4.5 eV), and low leakage current density (?10-6 A/cm2 at 1 V).

Khorshidi, Zahra; Bahari, Ali; Gholipur, Reza

2014-11-01

37

Development of Oxidation Sources in Preparation of High-TcOxide Superconductor Thin Films Using the Molecular Beam Epitaxy Method  

Microsoft Academic Search

Film preparation of oxide superconductors, mainly of the 1-2-3 (RBa2Cu3Ox) and Bi-containing (Bi-Sr-Ca-Cu-O) systems, by evaporation of either metals or metal compounds by low pressure is summarized, with a particular focus on the development of oxidation sources essential to the technique. Oxidizing reagents that enable the oxidation of metal evaporates to take place in high (0·1 to 10?3 Pa) or

Hidehiko Nonaka; Shingo Ichimura; Takashi Shimizu; Kazuo Arai

1995-01-01

38

Environmental reactivity characteristics of K 3C 60 and YBa 2Cu 3O 7-x high-temperature superconductor thin films  

NASA Astrophysics Data System (ADS)

Recently the environmental reactivity behavior of the copper-oxide superconductors has been studied and the following reactivity trends have been established: YBa 2Cu 3O 7 > Tl 2Ba 2Ca 2Cu 3O 10 > Bi 2Sr 2CaCu 2O 8 ? La 1.85Sr 0.15CuO 4 > Nd 1.85Ce 0.15CuO 4 > Nd 1.85Th 0.15CuO 4 In this paper, the degradation characteristics of the most reactive cuprate material, YBa 2Cu 3O 7, are compared with those of the fulleride superconductor, K 3C 60. Conductivity vs. exposure time measurements acquired for thin film samples in eight different environments are utilized to estimate the degradation rates for the superconductor materials. The cuprate superconductor remains relatively stable in the presence of dry nitrogen, dry oxygen, vacuum, air and acetonitrile environments, but degrades rapidly upon exposure to water solutions. Samples of K 3C 60 are also unreactive in dry nitrogen and under vacuum, but decompose extremely rapidly upon exposure to dry oxygen, air, acetonitrile or water solutions resulting in the complete loss of the superconducting properties.

Riley, David R.; Jurbergs, David; Zhou, Ji-Ping; Zhao, Jianai; McDevitt, John T.

1993-11-01

39

Thin Films  

NASA Astrophysics Data System (ADS)

Titanium dioxide (TiO2) thin films were synthesized on glass substrates by spray pyrolysis. The effect of solution flow rate on the physical properties of the films was investigated by use of x-ray diffraction (XRD), scanning electron microscopy, atomic force microscopy (AFM), and spectrophotometry techniques. XRD analysis revealed the tetragonal anatase phase of TiO2 with highly preferred (101) orientation. AFM images showed that grain size on top of TiO2 thin films depended on solution flow rate. An indirect band gap energy of 3.46 eV was determined by means of transmission and reflection measurements. The envelope method, based on the optical transmission spectrum, was used to determine film thickness and optical constants, for example real and imaginary parts of the dielectric constant, refractive index, and extinction coefficient. Ultraviolet and visible photoluminescence emission peaks were observed at room temperature. These peaks were attributed to the intrinsic emission and to the surface defect states, respectively.

Naffouti, Wafa; Nasr, Tarek Ben; Mehdi, Ahmed; Kamoun-Turki, Najoua

2014-11-01

40

Self-ordering of random intercalates in thin films of cuprate superconductors: Growth model and x-ray diffraction diagnosis  

SciTech Connect

We propose a simple model for the nucleation of random intercalates during the growth of high-temperature superconductor (HTSC) films by pulsed laser deposition (PLD). The model predicts a very particular spatial distribution of defects: a Markovian-like sequence of displacements along the growth direction (c axis), as well as a two-component in-plane correlation function, characteristic of self-organized intercalates. A model for x-ray diffraction (XRD) on such structures is also developed and accounts for both c-axis and in-plane anomalies observed in XRD experiments. The method presented in this work constitutes a useful characterization tool in the optimization of deposition parameters for the growth of HTSC films.

Ariosa, D.; Cancellieri, C.; Pavuna, D. [Laboratory of X-ray, EPFL SB-IPMC-LPRX, CH-1015 Lausanne (Switzerland); Lin, P. H. [Laboratory of X-ray, EPFL SB-IPMC-LPRX, CH-1015 Lausanne (Switzerland); Department of Engineering and System Science, National Tsing Hua University, TW-30013, Taiwan (China); Academia Sinica, Institute of Physics, TW-11529, Taiwan (China)

2007-05-01

41

Processing of Bi sbnd (Pb) sbnd Sr sbnd Ca sbnd Cu oxide superconductor thin films by metal alkoxide route  

NASA Astrophysics Data System (ADS)

High- Tc superconducting thin films in the Bi sbnd Pb sbnd Sr sbnd Ca sbnd Cu sbnd O system were prepared through reaction controls in organic solution by a metal-organic route. Thin films with preferred orientation were successfully prepared on MgO (100) single crystal substrates by a dip coating method. The films of the (243) phase (high- Tc phase) and the (232) phase (low- Tc phase) were synthesized from solutions with composition of Bi:Pb:Sr:Ca:Cu = 2:0.35:2:2:3 and Bi:Sr:Ca:Cu = 2:2:1:2, respectively. The Jc of films was much improved through the UV irradiation during calcination as well as the proper selection of composition for starting solutions. A film prepared from a solution composition of Bi:Pb:Sr:Ca:Cu = 2:0.35:2:2:3 with UV irradiation showed the sharp onset of Tc at 117 K, zero resistance at 79.5 K and Jc of 840 A/cm 2 (77.3 K) after heat treatment at 845°C.

Hirano, S.; Yogo, T.; Kikuta, K.; Tomonaga, H.; Ishii, M.

42

Thin Film Interference Model  

NSDL National Science Digital Library

The Thin Film Interference model investigates reflection and transmission of light through a thin film. The user can change the thickness and index of refraction of the thin film as well as the incident light wavelength. The Thin Film Interference Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_ThinFilm.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-25

43

Thin Film Perovskites  

Microsoft Academic Search

A multilayer perovskite thin film resistive memory device has been developed comprised of: a Pr0.7Ca0.3MnO3 (PCMO) perovskite oxide epitaxial layer on a YBCO bottom thin film electrode; a thin yttria stabilized zirconia (YSZ) buffer layer grown on the PCMO layer, and a gold thin film top electrode. The multi-layer thin film lattice structure has been characterized by XRD and TEM

Xin CHEN; Naijuan WU; Alex IGNATIEV

44

Epitaxial thin film growth in outer space  

NASA Technical Reports Server (NTRS)

A new concept for materials processing in space exploits the ultravacuum component of space for thin-film epitaxial growth. The unique LEO space environment is expected to yield 10-ftorr or better pressures, semiinfinite pumping speeds, and large ultravacuum volume (about 100 cu m) without walls. These space ultravacuum properties promise major improvement in the quality, unique nature, and throughput of epitaxially grown materials, including semiconductors, magnetic materials, and thin-film high-temperature superconductors.

Ignatiev, Alex; Chu, C. W.

1988-01-01

45

Pyrolyzed thin film carbon  

NASA Technical Reports Server (NTRS)

A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

2010-01-01

46

Quasiparticle generation efficiency in superconducting thin films  

NASA Astrophysics Data System (ADS)

Thin-film superconductors with thickness ˜30-500 nm are used as non-equilibrium quantum detectors for photons, phonons or more exotic particles. One of the most basic questions in determining their limiting sensitivity is the efficiency with which the quanta of interest couple to the detected quasiparticles. As low temperature superconducting resonators, thin films are attractive candidates for producing quantum-sensitive arrayable sensors and the readout uses an additional microwave probe. We have calculated the quasiparticle generation efficiency ?s for low energy photons in a representative, clean thin-film superconductor (Al) operating well below its superconducting transition temperature as a function of film thickness, within the framework of the coupled kinetic equations described by Chang and Scalapino (1978 J. Low Temp. Phys. 31 1-32). We have also included the effect of a lower frequency probe. We show that phonon loss from the thin film reduces ?s by as much as 40% compared to earlier models that considered relatively thick films or infinite volumes. We also show that the presence of the probe and signal enhances the generation efficiency slightly. We conclude that the ultimate limiting noise equivalent power of this class of detector is determined by the thin-film geometry.

Guruswamy, T.; Goldie, D. J.; Withington, S.

2014-05-01

47

Thin Films Module  

NSDL National Science Digital Library

This page from Nano-Link contains the document required for the thin films module. The activity requires a background in eight grade science. This 9 page guide includes background information on thin film interference, a hands-on learning activity, links to multimedia resources, and further readings. Visitors must complete a quick and free registration to access the materials.

2014-09-10

48

Studies of solution deposited cerium oxide thin films on textured Ni-alloy substrates for YBCO superconductor  

SciTech Connect

Cerium oxide (CeO{sub 2}) buffer layers play an important role for the development of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) based superconducting tapes using the rolling assisted biaxially textured substrates (RABiTS) approach. The chemical solution deposition (CSD) approach has been used to grow epitaxial CeO{sub 2} films on textured Ni-3 at.% W alloy substrates with various starting precursors of ceria. Precursors such as cerium acetate, cerium acetylacetonate, cerium 2-ethylhexanoate, cerium nitrate, and cerium trifluoroacetate were prepared in suitable solvents. The optimum growth conditions for these cerium precursors were Ar-4% H{sub 2} gas processing atmosphere, solution concentration levels of 0.2-0.5 M, a dwell time of 15 min, and a process temperature range of 1050-1150 deg. C. X-ray diffraction, AFM, SEM, and optical microscopy were used to characterize the CeO{sub 2} films. Highly textured CeO{sub 2} layers were obtained on Ni-W substrates with both cerium acetate and cerium acetylacetonate as starting precursors. YBCO films with a J {sub c} of 1.5 MA/cm{sup 2} were obtained on cerium acetylacetonate-based CeO{sub 2} films with sputtered YSZ and CeO{sub 2} cap layers.

Stewart, E. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Bhuiyan, M.S. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Sathyamurthy, S. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States); Paranthaman, M. [Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6100 (United States)]. E-mail: paranthamanm@ornl.gov

2006-06-15

49

Studies of Solution Deposited Cerium Oxide Thin Films on Textured Ni-Alloy Substractes for YBCO Superconductor  

SciTech Connect

Cerium oxide (CeO2) buffer layers play an important role for the development of YBa2Cu3O7-x (YBCO) based superconducting tapes using the rolling assisted biaxially textured substrates (RABiTS) approach. The chemical solution deposition (CSD) approach has been used to grow epitaxial CeO2 films on textured Ni-3 a 4% W alloy substrates with various starting precursors of ceria. Precursors such as cerium acetate, cerium acetylacetonate, cerium 2-ethylhexanoate, cerium nitrate, and cerium trifluoroacetate were prepared in suitable solvents. The optimum growth conditions for these cerium precursors were Ar-4% H2 gas processing atmosphere, solution concentration levels of 0.2-0.5 M, a dwell time of 15 min, and a process temperature range of 1050-1150 degrees C. X-ray diffraction, AFM, SEM, and optical microscopy were used to characterize the CeO2 films. Highly textured CeO2 layers were obtained on Ni-W substrates with both cerium acetate and cerium acetylacetonate as starting precursors. YBCO films with a Jc of 1.5 MA/cm2 were obtained on cerium acetylacetonate-based CeO2 films with sputtered YSZ and CeO2 cap layers.

Stewart, Erin L [ORNL; Bhuiyan, Md S [ORNL; Sathyamurthy, Srivatsan [ORNL; Paranthaman, Mariappan Parans [ORNL

2006-01-01

50

Thin film hydrogen sensor  

DOEpatents

A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

1999-03-23

51

Thin film hydrogen sensor  

DOEpatents

A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

Cheng, Yang-Tse (Rochester Hills, MI); Poli, Andrea A. (Livonia, MI); Meltser, Mark Alexander (Pittsford, NY)

1999-01-01

52

Dielectric Thin Films.  

NASA Astrophysics Data System (ADS)

Thin film technology is pervasive in the fabrication of all high performance integrated circuits. Success of this technology is due to its capability to achieve high volumetric efficiency by reducing the physical size of each element without disrupting its electrical performance. Along with other thin films, considerable attention has been paid in the area of ferroelectric thin films for device applications. Generally these films are amorphous in nature and an annealing process is required to enhance the crystallinity of the film. Measurement of dielectric properties of these films showed an increase in the values of dielectric constant and a decrease of coercive fields and annealing. Thus a larger volume efficiency can be achieved with ferroelectric materials. We chose to investigate ferroelectric antimony sulphur iodide (SbSI) and bismuth titanate (Bi(,4)Ti(,3)O(,12)) for dielectric thin film applications. SbSI is a member of the large family of A('V)B('VI)C('VII) ferroelectric compounds with a large anisotropy in the dielectric properties and a phase transition temperature at 20(DEGREES)C. It has a dielectric constant as high as 6.0 x 10('4) and a large pyroelectric coefficient of 60 x 10('3) (mu)c/m('2) (DEGREES)C at the phase transition. It also has very interesting piezoelectric properties. SbSI thin films were prepared by the vacuum thermal evaporation method. The c-axis oriented SbSI films were prepared by the recrystallization of as-grown films using a suitable annealing process. Bi(,4)Ti(,3)O(,12) is a member of the bismuth oxide layer structure family. The high Curie temperature (675(DEGREES)C) and mica-like morphology of the sheet structure suggest the potentiality of Bi(,4)Ti(,3)O(,12) as a stable thin film dielectric with high dielectric strength. Crystalline Bi(,4)Ti(,3)O(,12) films were deposited by RF sputtering in argon:oxygen gas atmosphere using heated substrates. Dielectric measurements on these films showed that SbSI thin films can be made reproducibly with the capacitance ranging up to 0.6 (mu)F/cm('2). Cracks due to high stress and pin-holes in films deteriorate the dielectric properties. On the other hand Bi(,4)Ti(,3)O(,12) films prepared on hot substrates showed permittivity (epsilon)(,R) > 200 and tan (delta) < 2%, suggesting the potential use of this material in thin film capacitors.

Ghosh, Prasanta K.

53

Formation of thin film Tl-based high-Tc? superconducting oxides from amorphous alloy precursors  

E-print Network

and satisfying. John Charles Williams TABLE OF CONTENTS ABSTRACT. ACKNOWLEDGMENTS. TABLE OF CONTENTS. LIST OF TABLES. LIST OF FIGURES. I. INTRODUCTION. 1v v vu1 A. Properties of Perovskites and Copper-Oxide Superconductors. . . . . . . . . 2 1.... Fundamental Properties. 2. Perovskite Crystal Structure. 3. Perovskite Crystal Structure Modifications 4, Structure of Thallate Superconductors . . B. Thallium-based Thin Film Superconductors. . . . 1. Tl-based Thin Film Production Methods. . . . 2...

Williams, John Charles

2012-06-07

54

Thin Film Growth  

NSDL National Science Digital Library

This is a PDF version of lecture slides that discuss thin film growth processes. Slide topics include plasma properties, DC glow discharge, ionization, plasma species, magnetrons, collisions, and chemical reactions. Numerous charts and mathematical formulas are presented.

Rack, Philip D.

2010-07-19

55

Protein Thin Film Machines  

E-print Network

We report the first example of microcantilever beams that are reversibly driven by protein thin film machines fuelled by cycling the salt concentration of the surrounding solution. We also show that upon the same salinity ...

Federici, Stefania

56

Ferroelectric thin films  

SciTech Connect

The area of ferroelectric thin films has expanded rapidly recently with the advent of high quality multi-oxide deposition technology. Advances in thin film quality has resulted in the realization of new technologies not achievable through classical bulk ceramic processing techniques. An example of this progress is the co-processing of ferroelectric thin films with standard semiconductor silicon and GaAs integrated circuits for radiation hard, non-volatile memory products. While the development of this class of products is still embryonic, the forecasted market potential is rapidly out distancing the combined developmental effort. Historically the greatest use of bulk ferroelectric material has been in sensor technology, utilizing the pyroelectric and piezoelectric properties of the material. By comparison, a relatively small development effort has been reported for ferroelectric thin film senor technology, a field sure to provide exciting advances in the future. The papers in this proceedings volume were presented at the first symposium dedicated to the field of ferroelectric thin films held by the Materials Research Society at the Spring 1990 Meeting in San Francisco, CA, April 16-20, 1990. The symposium was designed to provide a comprehensive tutorial covering the newest advances of ferroelectric thin films, including material systems, new deposition techniques and physical, electrical and electro-optic characterization.

Myers, E.R. (National Semiconductor Corp., Santa Clara, CA (United States)); Kingon, A.I. (North Carolina State Univ., Raleigh, NC (United States))

1990-01-01

57

Exploring Materials: Thin Films  

NSDL National Science Digital Library

In this activity, learners create a colorful bookmark using a super thin layer of nail polish on water. Learners discover that a thin film creates iridescent, rainbow colors. This is a very fun and engaging activity for learners, and a great way to talk about how nanoscale structures often affect a materials' properties. SAFETY: Do this activity in a well-ventilated area.

Network, Nanoscale I.; Sciencenter

2010-01-01

58

Thermionic vacuum arc (TVA) technique for magnesium thin film deposition  

NASA Astrophysics Data System (ADS)

In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB 2) superconductor thin film with the TVA technique.

Balbag, M. Z.; Pat, S.; Ozkan, M.; Ekem, N.; Musa, G.

2010-08-01

59

Thin film temperature sensor  

NASA Technical Reports Server (NTRS)

Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

Grant, H. P.; Przybyszewski, J. S.

1980-01-01

60

Thin film ceramic thermocouples  

NASA Technical Reports Server (NTRS)

A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

2011-01-01

61

Thin film composite actuators  

NASA Astrophysics Data System (ADS)

The mechanical properties of Ni50Ti50 deposited on Si substrates were studied focussing on the interaction of the film and substrate. This interaction determines the transformation characteristics through interface accommodation and mechanical constraints exerted by the substrate stiffness. Substrate stiffness, controlled by the film/substrate thickness ratio, was found to have a substantial influence on the output energy of the film/substrate composite. A switch type composite based on this knowledge was fabricated and tested. The thermo-mechanical properties of Terfenol-D thin films deposited on Si substrates were studied by static and dynamic measurements of film/substrate composite cantilevers. The Curie transition, (Delta) E effect and mechanical damping of the film were measured simultaneously. The stress in the film was controlled by annealing below the recrystallization temperature and determined to vary from -500 MPa, compression, in as deposited films to +480 MPa, tension, in annealed films. The Curie temperature shifts from 80 degree(s)C to 140 degree(s)C as the tension increases while the structure of the film remains amorphous. The stress change induced by annealing also drastically effects the film's damping characteristics. The (Delta) E effect of the amorphous material, about 20%, was used to estimate the magnetostriction, (lambda) s approximately equals 4 (DOT) 10-3.

Su, Quanmin; Kim, Taesung; Zheng, Yun; Wuttig, Manfred R.

1995-05-01

62

Hysteresis of transport critical currents in high-temperature Y1Ba2Cu3O7- x superconductors: bulk samples and thin films  

Microsoft Academic Search

The current-voltage characteristics and transport critical currents at T=4.2 K and 77.3 K in Y1Ba2Cu3O7-x bulk and thin film samples in magnetic fields up to 9 T have been measured. Large hysteresis of resistively measured critical currents was observed. This is caused by the magnetic field history as well as by the transport current history. An additional explanation of the

M. Majoros; M. Polak; V. Strbik; S. Benacka; S. Chromik; F. Hanic; V. Plechacek

1990-01-01

63

Thin film solar cell workshop  

NASA Technical Reports Server (NTRS)

A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

Armstrong, Joe; Jeffrey, Frank

1993-01-01

64

Thin-film optical initiator  

DOEpatents

A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

Erickson, Kenneth L. (Albuquerque, NM)

2001-01-01

65

NMR characterization of thin films  

DOEpatents

A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

Gerald, II, Rex E. (Brookfield, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Homer Glen, IL); Diaz, Rocio (Chicago, IL); Vukovic, Lela (Westchester, IL)

2008-11-25

66

Electrochromic thin films  

Microsoft Academic Search

An electrochromic material has the property of changing color when voltage is applied across it. It is possible electronically to alter a window's transmission and reflection properties by use of electrochromic thin films. This allows regulation of conductive and radiative heat transfer rates, with variable optical attenuation in the visible and infrared part of the solar radiation. Suitable materials for

C. Nyman; U. Gullenberg; M. Leppihalme

1987-01-01

67

Thin-film photovoltaics  

NASA Astrophysics Data System (ADS)

CdTe and CuIn1-xGaxSe2-ySy (CIGSS) are ideal candidates for thin-film solar cells. Present photovoltaic (PV) conversion efficiencies of champion thin-film solar cells are: CuIn1-xGaxSe2 (CIGS) 19.5%, CdTe 16.5%, and a-Si:H 12.4%. Thin-film PV modules could spearhead production growth of photovoltaics in the United States because of their added production capacity. For this purpose, module efficiencies must be improved to the 13%-15% range. Obtaining Ohmic contacts is difficult, especially for CdTe, because of the inherently low p-type doping level. Therefore, increasing the p-type doping level is important. Growth of CIGSS film must be controlled carefully as it transitions from Cu-rich to In-rich composition. Other issues for CIGSS cells are minimizing indium consumption, and increasing process throughput of selenization/sulfurization and transparent conducting oxide deposition. Development of all-dry processing for CdS deposition would be beneficial for both cells. This paper discusses basic devices and related issues.

Dhere, Neelkanth G.; Dhere, Ramesh G.

2005-07-01

68

A proposal for epitaxial thin film growth in outer space  

NASA Technical Reports Server (NTRS)

A new concept for materials processing in space exploits the ultravacuum component of space for thin film epitaxial growth. The unique low earth orbit space environment is expected to yield 10 to the -14th torr or better pressures, semiinfinite pumping speeds, and large ultravacuum volume without walls. These space ultravacuum properties promise major improvement in the quality, unique nature, and the throughput of epitaxially grown materials. Advanced thin film materials to be epitaxially grown in space include semiconductors, magnetic materials, and thin film high temperature superconductors.

Ignatiev, Alex; Chu, C. W.

1988-01-01

69

Biomimetic thin film deposition  

SciTech Connect

Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

1995-09-01

70

Advanced thin film thermocouples  

NASA Technical Reports Server (NTRS)

The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

Kreider, K. G.; Semancik, S.; Olson, C.

1984-01-01

71

thin films as absorber  

NASA Astrophysics Data System (ADS)

Photovoltaic structures were prepared using AgSb(S x Se1- x )2 as absorber and CdS as window layer at various conditions via a hybrid technique of chemical bath deposition and thermal evaporation followed by heat treatments. Silver antimony sulfo selenide thin films [AgSb(S x Se1- x )2] were prepared by heating multilayers of sequentially deposited Sb2S3/Ag dipped in Na2SeSO3 solution, glass/Sb2S3/Ag/Se. For this, Sb2S3 thin films were deposited from a chemical bath containing SbCl3 and Na2S2O3. Then, Ag thin films were thermally evaporated on glass/Sb2S3, followed by selenization by dipping in an acidic solution of Na2SeSO3. The duration of dipping was varied as 3, 4 and 5 h. Two different heat treatments, one at 350 °C for 20 min in vacuum followed by a post-heat treatment at 325 °C for 2 h in Ar, and the other at 350 °C for 1 h in Ar, were applied to the multilayers of different configurations. X-ray diffraction results showed the formation of AgSb(S x Se1- x )2 thin films as the primary phase and AgSb(S,Se)2 and Sb2S3 as secondary phases. Morphology and elemental detection were done by scanning electron microscopy and energy dispersive X-ray analysis. X-ray photoelectron spectroscopic studies showed the depthwise composition of the films. Optical properties were determined by UV-vis-IR transmittance and reflection spectral analysis. AgSb(S x Se1- x )2 formed at different conditions was incorporated in PV structures glass/FTO/CdS/AgSb(S x Se1- x )2/C/Ag. Chemically deposited post-annealed CdS thin films of various thicknesses were used as window layer. J- V characteristics of the cells were measured under dark and AM1.5 illumination. Analysis of the J- V characteristics resulted in the best solar cell parameters of V oc = 520 mV, J sc = 9.70 mA cm-2, FF = 0.50 and ? = 2.7 %.

González, J. O.; Shaji, S.; Avellaneda, D.; Castillo, G. A.; Das Roy, T. K.; Krishnan, B.

2014-09-01

72

Thin film composite electrolyte  

DOEpatents

The invention is a thin film composite solid (and a means for making such) suitable for use as an electrolyte, having a first layer of a dense, non-porous conductive material; a second layer of a porous ionic conductive material; and a third layer of a dense non-porous conductive material, wherein the second layer has a Coefficient of thermal expansion within 5% of the coefficient of thermal expansion of the first and third layers.

Schucker, Robert C. (The Woodlands, TX)

2007-08-14

73

Enhanced Superconducting Properties of Iron Chalcogenide Thin Films  

E-print Network

. Compared with its bulk counterpart, iron-based superconductor thin film has a great potential in developing the ordered quasi-2D structure and is suitable for coating technology which has already been applied in YBa_2Cu_3 O_7-x coated conductors...

Chen, Li

2013-07-26

74

Thin film mechanics  

NASA Astrophysics Data System (ADS)

This doctoral thesis details the methods of determining mechanical properties of two classes of novel thin films suspended two-dimensional crystals and electron beam irradiated microfilms of polydimethylsiloxane (PDMS). Thin films are used in a variety of surface coatings to alter the opto-electronic properties or increase the wear or corrosion resistance and are ideal for micro- and nanoelectromechanical system fabrication. One of the challenges in fabricating thin films is the introduction of strains which can arise due to application techniques, geometrical conformation, or other spurious conditions. Chapters 2-4 focus on two dimensional materials. This is the intrinsic limit of thin films-being constrained to one atomic or molecular unit of thickness. These materials have mechanical, electrical, and optical properties ideal for micro- and nanoelectromechanical systems with truly novel device functionality. As such, the breadth of applications that can benefit from a treatise on two dimensional film mechanics is reason enough for exploration. This study explores the anomylously high strength of two dimensional materials. Furthermore, this work also aims to bridge four main gaps in the understanding of material science: bridging the gap between ab initio calculations and finite element analysis, bridging the gap between ab initio calculations and experimental results, nanoscale to microscale, and microscale to mesoscale. A nonlinear elasticity model is used to determine the necessary elastic constants to define the strain-energy density function for finite strain. Then, ab initio calculations-density functional theory-is used to calculate the nonlinear elastic response. Chapter 2 focuses on validating this methodology with atomic force microscope nanoindentation on molybdenum disulfide. Chapter 3 explores the convergence criteria of three density functional theory solvers to further verify the numerical calculations. Chapter 4 then uses this model to investigate the role of grain boundaries on the strength of chemical vapor deposited graphene. The results from these studies suggest that two dimensional films have remarkably high strength-reaching the intrinsic limit of molecular bonds. Chapter 5 explores the viscoelastic properties of heterogeneous polydimethylsiloxane (PDMS) microfilms through dynamic nanoindentation. PDMS microfilms are irradiated with an electron beam creating a 3 m-thick film with an increased cross-link density. The change in mechanical properties of PDMS due to thermal history and accelerator have been explored by a variety of tests, but the effect of electron beam irradiation is still unknown. The resulting structure is a stiff microfilm embedded in a soft rubber with some transformational strain induced by the cross-linking volume changes. Chapter 5 employs a combination of dynamic nanoindentation and finite element analysis to determine the change in stiffness as a function of electron beam irradiation. The experimental results are compared to the literature. The results of these experimental and numerical techniques provide exciting opportu- nities in future research. Two dimensional materials and flexible thin films are exciting materials for novel applications with new form factors, such as flexible electronics and microfluidic devices. The results herein indicate that you can accurately model the strength of two dimsensional materials and that these materials are robust against nanoscale defects. The results also reveal local variation of mechanical properties in PDMS microfilms. This allows one to design substrates that flex with varying amounts of strain on the surface. Combining the mechanics of two dimensional materials with that of a locally irradiated PDMS film could achieve a new class of flexible microelectromechanical systems. Large-scale growth of two dimensional materials will be structurally robust-even in the presence of nanostructural defects-and PDMS microfilms can be irradiated to vary strain of the electromechanical systems. These systems could be designed to investigate e

Cooper, Ryan C.

75

Nonlinear optical thin films  

NASA Technical Reports Server (NTRS)

A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film-forming material in a working device is a complex, multifaceted endeavor. It requires close attention to maintaining the optical properties of the electro-optic active portion of the polymer while manipulating the polymer structure to obtain the desired secondary polymer properties.

Leslie, Thomas M.

1993-01-01

76

Thin film atomic hydrogen detectors  

NASA Technical Reports Server (NTRS)

Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.

Gruber, C. L.

1977-01-01

77

Critical-Point Fluctuations of Low-Frequency Noise in Yttrium BARIUM(2) COPPER(3) OXYGEN(7-DELTA) High Critical Temperature Superconductor Thin Films  

NASA Astrophysics Data System (ADS)

Measurements of the spectral density of the low frequency 1/f^{alpha} noise in YBa_2Cu_3 O_{7-delta} thin films made by MOCVD, laser ablation, and inverted cylindrical magnetron sputtering reveal a critical point divergence both in the noise power, S_{f }, and in the exponent, alpha . As the temperature approaches T_ {c}, the noise power increases by four orders of magnitude reaching a maximum at the tail of the superconducting transition region. Similarly the exponent alpha diverges from a value near unity at room temperature to a value above 2.0. A model is proposed to interpret the critical point divergence of 1/f noise power as fluctuations in the number of correlated electron-pairs. The theoretical estimation is based on the phenomenological Ginzburg-Landau theory. The conductivity fluctuations due to the superconducting mechanisms reveal {1 over T-T_{c}} dependence. Since the 1/f noise is a measurement of resistance fluctuations, the noise power a divergences as {1 over (T-T_{c })^2} as the temperature approaches rm T_{c}.

Wang, Annie Qing

78

Fabrication of high-quality superconductor-insulator-superconductor junctions on thin SiN membranes  

NASA Technical Reports Server (NTRS)

We have successfully fabricated high-quality and high-current density superconductor-insulator-superconductor (SIS) junctions on freestanding thin silicon nitride (SIN) membranes. These devices can be used in a novel millimeter-wave and THz receiver system which is made using micromachining. The SIS junctions with planar antennas were fabricated first on a silicon wafer covered with a SiN membrane, the Si wafer underneath was then etched away using an anisotropic KOH etchant. The current-voltage characteristics of the SIS junctions remained unchanged after the whole process, and the junctions and the membrane survived thermal cycling.

Garcia, Edouard; Jacobson, Brian R.; Hu, Qing

1993-01-01

79

Evolution of structural perfections in high Tc superconducting thin film  

NASA Astrophysics Data System (ADS)

In this dissertation work, I developed a forensic methodology to investigate the evolution of chemistry and superconductivity in a heteroepitaxial thin film system---YBa2Cu3O6+x (YBCO). Misfit lattice of a YBCO thin film and its substrate results in coherency strain that dictates the generation of oxygen deficiency and structural defects, which is eventually manifested in the superconductivity or normal state properties. To understand the dynamic process of such evolution, in my retrospective approach, a thicker film is stripped thinner step by step and then compared with an as-grown film of equal thickness. Through such one-to-one comparison, I succeeded in characterizing the effects of strain, partial strain-relaxation, and complete strain-relaxation on the chemistry and physics of thin film cuprate high temperature superconductors as probed by various analytical tools.

Seo, Hye-Won

80

Thin film hydrogen sensor  

DOEpatents

A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.

1994-11-22

81

Composite Thin Films  

SciTech Connect

Composites are one of more versatile types of materials, and can be characterized as multicomponent, or multiphase, mixtures. They can have unique structural, optical, electrical and magnetic properties not possible with a simple single component material. One of the best known composite materials is fiberglass, which is composed of glass fibers in a polymer matrix. This family of materials and thin films is highly disordered and inhomogeneous on a microstructural scale. Nanocrystalline and nanoclusters are now actively being investigated. The inhomogeneities can be fibers, clusters of atoms or molecules, grains with different crystalline phases (nanocrystalline clusters), inclusions with different electrical and magnetic properties. Note that the particles can have the same composition as the host material, but will have a different structural geometry. Carbon-carbon composites are a good example, where carbon fibers or threads are incorporated into carbonaceous resin

Martin, Peter M.

2003-02-01

82

Polyimide Aerogel Thin Films  

NASA Technical Reports Server (NTRS)

Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

Meador, Mary Ann; Guo, Haiquan

2012-01-01

83

Thin-film microextraction.  

PubMed

The properties of a thin sheet of poly(dimethylsiloxane) (PDMS) membrane as an extraction phase were examined and compared to solid-phase microextraction (SPME) PDMS-coated fiber for application to semivolatile analytes in direct and headspace modes. This new PDMS extraction approach showed much higher extraction rates because of the larger surface area to extraction-phase volume ratio of the thin film. Unlike the coated rod formats of SPME using thick coatings, the high extraction rate of the membrane SPME technique allows larger amounts of analytes to be extracted within a short period of time. Therefore, higher extraction efficiency and sensitivity can be achieved without sacrificing analysis time. In direct membrane SPME extraction, a linear relationship was found between the initial rate of extraction and the surface area of the extraction phase. However, for headspace extraction, the rates were somewhat lower because of the resistance to analyte transport at the sample matrix/headspace barrier. It was found that the effect of this barrier could be reduced by increasing either agitation, temperature, or surface area of the sample matrix/headspace interface. A method for the determination of PAHs in spiked lake water samples was developed based on the membrane PDMS extraction coupled with GC/MS. A linearity of 0.9960 and detection limits in the low-ppt level were found. The reproducibility was found to vary from 2.8% to 10.7%. PMID:12622398

Bruheim, Inge; Liu, Xiaochuan; Pawliszyn, Janusz

2003-02-15

84

Superconducting properties of iron chalcogenide thin films  

NASA Astrophysics Data System (ADS)

Iron chalcogenides, binary FeSe, FeTe and ternary FeTexSe1-x, FeTexS1-x and FeTe:Ox, are the simplest compounds amongst the recently discovered iron-based superconductors. Thin films of iron chalcogenides present many attractive features that are covered in this review, such as: (i) easy fabrication and epitaxial growth on common single-crystal substrates; (ii) strong enhancement of superconducting transition temperature with respect to the bulk parent compounds (in FeTe0.5Se0.5, zero-resistance transition temperature Tc0bulk = 13.5 K, but Tc0film = 19 K on LaAlO3 substrate); (iii) high critical current density (Jc ˜ 0.5 ×106 A cm2 at 4.2 K and 0 T for FeTe0.5Se0.5 film deposited on CaF2, and similar values on flexible metallic substrates (Hastelloy tapes buffered by ion-beam assisted deposition) with a weak dependence on magnetic field; (iv) high upper critical field (˜50 T for FeTe0.5Se0.5, Bc2(0), with a low anisotropy, ? ˜ 2). These highlights explain why thin films of iron chalcogenides have been widely studied in recent years and are considered as promising materials for applications requiring high magnetic fields (20-50 T) and low temperatures (2-10 K).

Mele, Paolo

2012-10-01

85

Spontaneous vortices in ferromagnet-superconductor systems  

E-print Network

We study the interaction between superconductors and ferromagnets in two systems: a ferromagnet-superconductor bilayer, and a thin superconducting film with a periodic array of magnetic dots upon it, with spontaneous vortices appearing...

Wei, Hongduo

2006-08-16

86

Modified thin film processing sequence  

SciTech Connect

A modified thin film processing sequence in which tantalum nitride (TA/sub 2/N) resistors are stabilized prior to chromium/gold (Cr/Au) evaporation was investigated, and the effects of subsequent processing on unstabilized Cr/Au films were determined. Thin films evaporated using the modified process yielded results similar to those of films evaporated using the standard processing techniques. Work on the modified process was discontinued because of some metallization adhesion failures at the Cr/Au-to-Ta/sub 2/N interface, higher contact resistance, and the additional steps required in processing.

Baxter, C.R.

1980-06-01

87

System for depositing thin films  

NASA Technical Reports Server (NTRS)

A system for depositing a thin film of one material on another is described. A mass filter is interposed between the source of material being deposited and the object upon which deposition is being made.

Tashbar, P. W. (inventor)

1974-01-01

88

Surfactant instabilities on thin films  

E-print Network

The deposition of a surfactant drop over a thin liquid film may be accompanied by a fingering instability. In this work, we present experimental results which identify the critical parameters that govern the shape and ...

Aessopos, Angelica

2005-01-01

89

Vertically Aligned Nanocomposite Thin Films  

E-print Network

and epitaxial growth ability on given substrates. In the present work, we investigated unique epitaxial two-phase VAN (BiFeO 3)x:(Sm2O 3)1-x and (La0.7Sr0.3MnO 3)x:(Mn3 O4)1-x thin film systems by pulsed laser deposition. These VAN thin films exhibit a highly...

Bi, Zhenxing

2012-07-16

90

Thin-Film Resistive Heater  

NASA Technical Reports Server (NTRS)

Thin-film electrically resistive heater applies high, controlled flux of heat to surface of object. Heater mounted directly on surface of object. It is small, simple to operate, and less expensive than laser and arc heating facilities. Because only other equipment needed appropriate power supply, thin-film heater essentially portable device useful in wide range of eventual applications in research and in field.

Scotti, Stephen J.

1994-01-01

91

Mechanical properties of thin films  

Microsoft Academic Search

The mechanical properties of thin films on substrates are described and studied. It is shown that very large stresses may\\u000a be present in the thin films that comprise integrated circuits and magnetic disks and that these stresses can cause deformation\\u000a and fracture to occur. It is argued that the approaches that have proven useful in the study of bulk structural

William D. Nix

1989-01-01

92

Thin film cell development workshop report  

NASA Technical Reports Server (NTRS)

The Thin Film Development Workshop provided an opportunity for those interested in space applications of thin film cells to debate several topics. The unique characteristics of thin film cells as well as a number of other issues were covered during the discussions. The potential of thin film cells, key research and development issues, manufacturing issues, radiation damage, substrates, and space qualification of thin film cells were discussed.

Woodyard, James R.

1991-01-01

93

thin film capacitors  

NASA Astrophysics Data System (ADS)

CaCu3Ti4O12 (CCTO) thin films were grown by pulsed laser deposition on Pt and La0.9Sr1.1NiO4 (LSNO) bottom electrodes. The electrical characteristics of the CCTO/Pt and CCTO/LSNO Schottky junctions have been analyzed by impedance spectroscopy, capacitance-voltage (C-V) and current-voltage (I-V) measurements as a function of frequency (40 Hz-1 MHz) and temperature (300-475 K). Similar results were obtained for the two Schottky diodes. The conduction mechanism through the Schottky junctions was described using a thermionic emission model and the electrical parameters were determined. The strong deviation from the ideal I-V characteristics and the increase in capacitance at low frequency for -0.5 V bias are in agreement with the presence of traps near the interfaces. Results point toward the important effect of defects generated at the interface by deposition of CCTO.

Bodeux, Romain; Gervais, Monique; Wolfman, Jérôme; Gervais, François

2014-09-01

94

Multilayer Thin-Film Microcapacitors  

NASA Technical Reports Server (NTRS)

Miniature capacitors containing multiple alternating thin-film dielectric and metal layers proposed, especially for use in integrated and hybrid electronic circuits. Because capacitance inversely proportional to thickness of dielectric layers, use of thin, high-quality dielectric layers affords capacitance and energy-storage densities much greater than now available. These devices much smaller and more reliable than state-of-art capacitors.

Thakoor, Sarita; Thakoor, Anil; Karmon, Dan

1995-01-01

95

Thin-Film Power Transformers  

NASA Technical Reports Server (NTRS)

Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

Katti, Romney R.

1995-01-01

96

Process for forming epitaxial perovskite thin film layers using halide precursors  

DOEpatents

A process for forming an epitaxial perovskite-phase thin film on a substrate. This thin film can act as a buffer layer between a Ni substrate and a YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor layer. The process utilizes alkali or alkaline metal acetates dissolved in halogenated organic acid along with titanium isopropoxide to dip or spin-coat the substrate which is then heated to about 700.degree. C. in an inert gas atmosphere to form the epitaxial film on the substrate. The YBCO superconductor can then be deposited on the layer formed by this invention.

Clem, Paul G. (Albuquerque, NM); Rodriguez, Mark A. (Albuquerque, NM); Voigt, James A. (Corrales, NM); Ashley, Carol S. (Albuquerque, NM)

2001-01-01

97

Thin films in energy systems  

Microsoft Academic Search

The development and use of thin plastic films as structural materials is discussed. The employment of air supported structure greenhouses utilizing very low cost highly transparent plastic film with a good life potential makes it possible to raise tomatoes in Ohio at costs which are much lower than those incurred in connection with the use of glass greenhouses. Attention is

R. S. Ross

1976-01-01

98

Thin film corrosion. Final report  

SciTech Connect

Corrosion of chromium/gold (Cr/Au) thin films during photolithography, prebond etching, and cleaning was evaluated. Vapors of chromium etchant, tantalum nitride etchant, and especially gold etchant were found to corrosively attack chromium/gold films. A palladium metal barrier between the gold and chromium layers was found to reduce the corrosion from gold etchant.

Raut, M.K.

1980-06-01

99

Metallurgical coatings and thin films; Proceedings of the International Conference, 18th, San Diego, CA, Apr. 22-26, 1991. Vols. 1 & 2  

NASA Technical Reports Server (NTRS)

A conference on metallurgical coatings and thin films produced papers in the areas of coatings for use at high temperatures; hard coatings and deposition technologies; diamonds and related materials; tribological coatings/surface modifications; thin films for microelectronics and high temperature superconductors; optical coatings, film characterization, magneto-optics, and guided waves; and methods for characterizing films and modified surfaces.

Mcguire, Gary E. (editor); Mcintyre, Dale C. (editor); Hofmann, Siegfried (editor)

1991-01-01

100

Receiver protecting device based on microstrip structure with high-temperature superconductor film  

NASA Astrophysics Data System (ADS)

New design of an effective device for protection against high-power electromagnetic pulses has been created based on a pair of noninteracting microstrip resonators, which are coupled in the working frequency band via a third resonator based on a thin film of high-temperature superconductor (HTSC) occurring in the superconducting state. Under the action of an electromagnetic pulse with the power above a certain threshold, the HTSC film element passes from the superconducting to normal (high-resistivity) state, thus breaking the coupling between resonators. This leads to power limitation at the device output due to a strong signal reflection from the input.

Belyaev, B. A.; Govorun, I. V.; Leksikov, A. A.; Serzhantov, A. M.

2012-03-01

101

Calorimetry of epitaxial thin films  

NASA Astrophysics Data System (ADS)

Thin film growth allows for the manipulation of material on the nanoscale, making possible the creation of metastable phases not seen in the bulk. Heat capacity provides a direct way of measuring thermodynamic properties of these new materials, but traditional bulk calorimetric techniques are inappropriate for such a small amount of material. Microcalorimetry and nanocalorimetry techniques exist for the measurements of thin films but rely on an amorphous membrane platform, limiting the types of films which can be measured. In the current work, ion-beam-assisted deposition is used to provide a biaxially oriented MgO template on a suspended membrane microcalorimeter in order to measure the specific heat of epitaxial thin films. Synchrotron x-ray diffraction showed the biaxial order of the MgO template. X-ray diffraction was also used to prove the high quality of epitaxy of a film grown onto this MgO template. The contribution of the MgO layer to the total heat capacity was measured to be just 6.5% of the total addenda contribution. The heat capacity of a Fe.49Rh.51 film grown epitaxially onto the device was measured, comparing favorably to literature data on bulk crystals. This shows the viability of the MgO/SiNx-membrane-based microcalorimeter as a way of measuring the thermodynamic properties of epitaxial thin films.

Cooke, David W.; Hellman, F.; Groves, J. R.; Clemens, B. M.; Moyerman, S.; Fullerton, E. E.

2011-02-01

102

Epitaxial antiperovskite superconducting CuNNi3 thin films synthesized by chemical solution deposition.  

PubMed

Epitaxial antiperovskite superconducting CuNNi3 thin films have been grown by chemical solution deposition. The film is a type II superconductor and shows a Tc of 3.2 K with a transition of 0.13 K. The Hc2(0) and ?0 are estimated to be 8.1 kOe and 201 Å, respectively. PMID:25197779

Hui, Zhenzhen; Tang, Xianwu; Shao, Dingfu; Lei, Hechang; Yang, Jie; Song, Wenhai; Luo, Hongmei; Zhu, Xuebin; Sun, Yuping

2014-09-25

103

Optical and electrical properties of thin superconducting films  

NASA Technical Reports Server (NTRS)

Infrared spectroscopic techniques can provide a vital probe of the superconducting energy gap which is one of the most fundamental physical properties of superconductors. Currently, the central questions regarding the optical properties of superconductors are how the energy gap can be measured by infrared techniques and at which frequency the gap exists. An effective infrared spectroscopic method to investigate the superconducting energy gap, Eg, was developed by using the Bomem DA 3.01 Fourier Transformation Spectrophotometer. The reflectivity of a superconducting thin film of YBaCuO deposited on SrTiO3 was measured. A shoulder was observed in the superconducting state reflectance R(sub S) at 480/cm. This gives a value of Eg/kT(sub c) = 7.83, where k is the Boltzmann constant and T(sub c) is the superconducting transition temperature, from which, it is suggested that YBaCuO is a very strong coupling superconductor.

Covington, Billy C.; Jing, Feng Chen

1990-01-01

104

Epitaxial gadolinium nitride thin films  

SciTech Connect

GdN thin films are deposited on MgO(100) by low-energy ion-beam-assisted molecular-beam epitaxy at elevated temperatures. Elemental analysis by secondary-ion mass spectrometry proves that a protective layer is imperative to avoid oxidation of the GdN films in air. In situ surface structural investigation of the growing GdN films by reflection high-energy electron diffraction reveals epitaxial film growth. This result is confirmed by x-ray diffraction structure and texture analysis. Accordingly, the GdN films on MgO(100) exhibit cube-on-cube epitaxy. Due to the epitaxial growth the crystalline quality of the films is by far higher than that of films previously reported of in literature.

Gerlach, J. W.; Mennig, J.; Rauschenbach, B. [Leibniz-Institut fuer Oberflaechenmodifizierung (IOM), Permoserstrasse 15, D-04318 Leipzig (Germany)

2007-02-05

105

Nanocrystalline chitin thin films.  

PubMed

Elucidating the interactions between crystalline chitin and various biomacromolecules is of fundamental importance for designing and fabricating chitin-based biomaterials. This work highlights a simple method to prepare ultrathin films of chitin nanocrystals (chitin NC) by spincoating chitin NCs from a colloidal suspension onto a gold surface modified by an amine-terminated self-assembled monolayer. Atomic force microscopy confirmed that chitin NC films are reasonably smooth and homogeneous, and quartz crystal microbalance with dissipation monitoring (QCM-D) solvent exchange experiments demonstrated that chitin NC films have twice as much water as amorphous regenerated chitin (RChitin) films of similar thickness. QCM-D data also showed that chitinase-catalyzed hydrolysis of chitin NC films was much slower than that of RChitin films. Chitinase not only degraded, but also caused the swelling of the chitin nanocrystals. BSA adsorption studies demonstrated that chitin NC films have high protein loading capacity, and thus show potential applications for enzyme immobilization. PMID:24507267

Wang, Chao; Esker, Alan R

2014-02-15

106

Drop dynamics on a thin film: Thin film rupture  

NASA Astrophysics Data System (ADS)

The spreading of a water drop on an oil film that covers a solid substrate is a common event in many industrial processes. We study in experiments the dynamics of a water drop on a thin silicone oil film and quantify its interaction with the solid substrate that supports the film. The oil film becomes unstable and ruptures for solids that are hydrophilic. We determine the ``waiting time,'' the time it takes the water drop to drain the silicone film. This timescale is found to highly depend on how well water wets the solid, illustrating the interplay between intermolecular and hydrodynamic forces in the phenomenon. A phase diagram for the thin film stability is extracted based on waters equilibrium contact angle on the solid, which shows that we can either promote or inhibit de-wetting. As water comes in direct contact with the solid, it spreads and peels off the silicone film. We show the influence of viscosity, equilibrium contact angle and film height on the opening radius of the hole formed as the solid de-wets.

Carlson, Andreas; Kim, Pilnam; Stone, Howard A.

2011-11-01

107

Drying of thin colloidal films  

NASA Astrophysics Data System (ADS)

When thin films of colloidal fluids are dried, a range of transitions are observed and the final film profile is found to depend on the processes that occur during the drying step. This article describes the drying process, initially concentrating on the various transitions. Particles are seen to initially consolidate at the edge of a drying droplet, the so-called coffee-ring effect. Flow is seen to be from the centre of the drop towards the edge and a front of close-packed particles passes horizontally across the film. Just behind the particle front the now solid film often displays cracks and finally the film is observed to de-wet. These various transitions are explained, with particular reference to the capillary pressure which forms in the solidified region of the film. The reasons for cracking in thin films is explored as well as various methods to minimize its effect. Methods to obtain stratified coatings through a single application are considered for a one-dimensional drying problem and this is then extended to two-dimensional films. Different evaporative models are described, including the physical reason for enhanced evaporation at the edge of droplets. The various scenarios when evaporation is found to be uniform across a drying film are then explained. Finally different experimental techniques for examining the drying step are mentioned and the article ends with suggested areas that warrant further study.

Routh, Alexander F.

2013-04-01

108

(Thin films under chemical stress)  

SciTech Connect

As stated above the purpose of this research is to enable workers in a variety of fields to understand the chemical and physical changes which take place when thin films (primarily organic films) are placed under chemical stress. This stress may occur because the film is being swelled by penetrant entrained in solvent, because interfacial reactions are occurring at one or more boundaries within the film structure, or because some component of the film is responding to an external stimulus (e.g. pH, temperature, electric field, or radiation). These questions are important within the context of our long-term goal of understanding the behavior of composite structures, composed of thin organic polymer films interspersed with Langmuir-Blodgett (LB) and self-assembled monolayers, which might have unique functional properties. In the past year we have concentrated on the following objectives: (1) understanding how the two possible diffusion mechanisms contribute to the swelling of thin films of organic polymers place in solution, (2) identifying systems which are appropriate polymer media for the construction of composite membranes for use in aqueous environments, and (3) understanding the self-assembly process for long chain fatty acids at model surfaces. Progress in meeting each of these objectives will be described in this report. 4 figs.

Not Available

1990-01-01

109

Thin films under chemical stress  

SciTech Connect

The goal of work on this project has been develop a set of experimental tools to allow investigators interested in transport, binding, and segregation phenomena in composite thin film structures to study these phenomena in situ. Work to-date has focuses on combining novel spatially-directed optical excitation phenomena, e.g. waveguide eigenmodes in thin dielectric slabs, surface plasmon excitations at metal-dielectric interfaces, with standard spectroscopies to understand dynamic processes in thin films and at interfaces. There have been two main scientific thrusts in the work and an additional technical project. In one thrust we have sought to develop experimental tools which will allow us to understand the chemical and physical changes which take place when thin polymer films are placed under chemical stress. In principle this stress may occur because the film is being swelled by a penetrant entrained in solvent, because interfacial reactions are occurring at one or more boundaries within the film structure, or because some component of the film is responding to an external stimulus (e.g. pH, temperature, electric field, or radiation). However all work to-date has focused on obtaining a clearer understanding penetrant transport phenomena. The other thrust has addressed the kinetics of adsorption of model n-alkanoic acids from organic solvents. Both of these thrusts are important within the context of our long-term goal of understanding the behavior of composite structures, composed of thin organic polymer films interspersed with Langmuir-Blodgett (LB) and self-assembled monolayers. In addition there has been a good deal of work to develop the local technical capability to fabricate grating couplers for optical waveguide excitation. This work, which is subsidiary to the main scientific goals of the project, has been successfully completed and will be detailed as well. 41 refs., 10 figs.

Not Available

1991-01-01

110

Characterization of sculptured thin films  

SciTech Connect

Physical vapor deposition can be used to synthesize sculptured thin films with high surface areas. Highly directional vapor deposition onto a tilted, rotating substrate has been shown to produce nanostructured materials with controlled columnar features, including zig-zag, cusp, chevron, and helical geometries. Nanoporous coatings such as these are desirable for optical sensing applications due to their accessible high surface area, but few techniques are available to quantify the surface area of thin films. Electron beam and thermal evaporation techniques are used to synthesize highly porous thin films from silicon dioxide and a germanium antimony selenide chalcogenide glass in order to explore their potential for optical applications in both the visible and infrared spectral ranges. Characterization has been performed using nitrogen adsorption isotherms obtained with a quartz crystal microbalance. It is shown that surface area can be increased up to 375 times that of a flat film by deposition at oblique angles. A nitrogen adsorption technique is introduced as a means to examine the porosity of sculptured thin films at a nanoscale.

Ryan, Joseph V.; Horn, Mark; Lakhtakia, Ashlesh; Pantano, C. G.

2004-05-11

111

Nanomechanical properties of hydrated organic thin films  

E-print Network

Hydrated organic thin films are biological or synthetic molecularly thin coatings which impart a particular functionality to an underlying substrate and which have discrete water molecules associated with them. Such films ...

Choi, Jae Hyeok

2007-01-01

112

Semiconductor-nanocrystal/conjugated polymer thin films  

DOEpatents

The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

Alivisatos, A. Paul (Oakland, CA); Dittmer, Janke J. (Munich, DE); Huynh, Wendy U. (Munich, DE); Milliron, Delia (Berkeley, CA)

2010-08-17

113

Thin film-coated polymer webs  

DOEpatents

The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)

1992-02-04

114

Calorimetry of epitaxial thin films  

NASA Astrophysics Data System (ADS)

Thin film growth allows for the manipulation of material on the nanoscale, allowing for the creation of metastable phases not seen in the bulk. Heat capacity provides a direct way of measuring thermodynamic properties of these new materials, but traditional bulk calorimetric techniques are inappropriate for such a small amount of material. Micro- and nanocalorimetry techniques exist for the measurements of thin films but rely on an amorphous membrane platform, limiting the types of films which can be measured. In this work, ion-beam-assisted deposition is used to provide a biaxially-oriented MgO template on a suspended membrane microcalorimeter. Synchrotron X-ray diffraction was used to successfully assess the biaxial order of the MgO template. X-ray diffraction was also used to prove the high level of epitaxy of a film grown onto this MgO template. The contribution of the MgO layer to the technique will be discussed. An Fe.49Rh.51 film grown epitaxially onto the device was measured, comparing favorably to literature data on bulk crystals. This shows the viability of the MgO microcalorimeter as a way of measuring the thermodynamic properties of epitaxial thin films.

Hellman, Frances; Cooke, David; Groves, James; Clemens, Bruce

2011-03-01

115

High Temperature Superconducting Thin Film Magnets  

NASA Astrophysics Data System (ADS)

YBCO thin film double pancake units can be fabricated on a single wafer. It is possible to produce 5 tesla induction at 4.2 K in a background field of about 20 tesla by stacking these double pancake wafers. Small YBCO thin film flat coils can produce useful fields that can be very beneficial for MEMs. We have fabricated a proof-of-concept thin film coil from our YBCO thin films and tested it successfully.

Hascicek, Y. S.; Eyssa, Y.; van Sciver, S. W.; Schneider-Muntau, H. J.

2004-11-01

116

Polyimide thin-film dielectrics on ferroelectrics  

NASA Technical Reports Server (NTRS)

Conducting layers of multi-layered thin-film ferroelectric device, such as is used in liquid crystal/ferroelectric display, can be electrically isolated using thin-film layer of polyimide. Ease of application and high electrical-breakdown strength allow dependable and economical means of providing dielectric for other thin-film microelectronic devices.

Galiardi, R. V.

1977-01-01

117

Propagation of Rayleigh waves in thin films  

Microsoft Academic Search

With the advent of thin film technology and more recently its applications in microelectronics and control of surface properties, the interest in mechanical properties of thin films has grown tremendously. Mechanical defects such as creep, fracture and adhesion loss, play a very important role in physical instabilities of thin film materials. An acoustic microscope has been built to study mechanical

Agus A. Ananda

1997-01-01

118

Hybrid thin-film amplifier  

NASA Technical Reports Server (NTRS)

Miniature amplifier for bioelectronic instrumentation consumes only about 100 mW and has frequency response flat to within 0.5 dB from 0.14 to 450 Hz. Device consists of five thin film substrates, which contain eight operational amplifiers and seven field-effect transistor dice.

Cleveland, G.

1977-01-01

119

Gridded thin film solar cell  

Microsoft Academic Search

An improved transparent conductor structure for thin film solar cells comprising a plurality of metallic strip conductors deposited on a transparent conductor and aligned substantially with the principal direction of current flow. The strip conductors preferably originate at an edge of the transparent conductor to which an adjacent cell back conductor is connected and are preferably interconnected along that edge

D. P. Tanner; R. R. Gay; D. L. Morel

1985-01-01

120

Thin Film Solid Lubricant Development  

NASA Technical Reports Server (NTRS)

Tribological coatings for high temperature sliding applications are addressed. A sputter-deposited bilayer coating of gold and chromium is investigated as a potential solid lubricant for protection of alumina substrates during sliding at high temperature. Evaluation of the tribological properties of alumina pins sliding against thin sputtered gold films on alumina substrates is presented.

Benoy, Patricia A.

1997-01-01

121

Thin films and uses  

DOEpatents

The invention provides a method for synthesizing a titanium oxide-containing film comprising the following steps: (a) preparing an aqueous solution of a titanium chelate with a titanium molarity in the range of 0.01M to 0.6M. (b) immersing a substrate in the prepared solution, (c) decomposing the titanium chelate to deposit a film on the substrate. The titanium chelate maybe decomposed acid, base, temperature or other means. A preferred method provides for the deposit of adherent titanium oxide films from C2 to C5 hydroxy carboxylic acids. In another aspect the invention is a novel article of manufacture having a titanium coating which protects the substrate against ultraviolet damage. In another aspect the invention provides novel semipermeable gas separation membranes, and a method for producing them.

Baskaran, Suresh (Kennewick, WA); Graff, Gordon L. (Kennewick, WA); Song, Lin (Richland, WA)

1998-01-01

122

Thin-Film Metamaterials Called Sculptured Thin Films  

Microsoft Academic Search

\\u000a Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples.\\u000a STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition\\u000a onto rotating substrates. The curvilinear-nanowire morphology of STFs is determined by the substrate motions during fabrication.\\u000a The optical properties, especially, can be tailored by varying the

Akhlesh Lakhtakia; Joseph B. Geddes III

2010-01-01

123

high-k thin films  

NASA Astrophysics Data System (ADS)

The local symmetries around the Hf sites in thin films of Hf1- x Zr x O2/Si(100) were probed using grazing incidence extended X-ray absorption fine-structure spectroscopy (EXAFS). The effects of the Zr incorporation on the local crystal symmetries were investigated using Hf L3 EXAFS at the Beamline X23A2 of the Brookhaven National Laboratory. The Zr ratios in the various films were set to between 0.0 and 1.0. Significant changes in the local environment were observed for x = 0.25 or greater values. For x = 0.0, the film local structure around Hf sites remain in the equilibrium monoclinic phase as referenced from our previous studies on HfO2 thin films on Si(100). When Zr is introduced, tetragonal symmetry around the Hf atom appears and becomes dominant at x = 0.63. Using the EXAFS theoretical simulations and non-linear least-square fit results, the fractions of the monoclinic versus tetragonal phases were identified in each film.

Sahiner, M. A.; Lysaght, P. S.; Price, J.; Kirsch, P. D.; Woicik, J. C.; Klump, A.; Reehil, C.; Manners, W. A.; Nabizadeh, A.

2014-10-01

124

Sputtered thin film research  

Microsoft Academic Search

The reactive RF sputtering technique was applied to the preparation of a wide variety of materials. Single crystal films of ZnO, TiO2, WO3 AlN and GaN were grown on one or more of the insulating crystalline substrates of Al2O3, MgAl2O3, SiC and LiNbO3. Data on the deposition parameters, structure and optical waveguiding characteristics of the heteroepitaxial structures are presented. Reactive

A. J. Shuskus; D. J. Quinn; E. L. Paradis; J. M. Berak; D. E. Cullen

1974-01-01

125

Thin film buried anode battery  

DOEpatents

A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

Lee, Se-Hee (Lakewood, CO); Tracy, C. Edwin (Golden, CO); Liu, Ping (Denver, CO)

2009-12-15

126

Thin Films Using Al Doping  

NASA Astrophysics Data System (ADS)

We have studied the influence of Al doping on the microstructural, optical, and electrical properties of spray-deposited WO3 thin films. XRD analyses confirm that all the films are of polycrystalline WO3 in nature, possessing monoclinic structure. EDX profiles of the Al-doped films show aluminum peaks implying incorporation of Al ions into WO3 lattice. On Al doping, the average crystallite size decreases due to increase in the density of nucleation centers at the time of film growth. The observed variation in the lattice parameter values on Al doping is attributed to the incorporation of Al ions into WO3 lattice. Enhancement in the direct optical band gap compared to the undoped film has been observed on Al doping due to decrease in the width of allowed energy states near the conduction band edge. The refractive indices of the films follow the Cauchy relation of normal dispersion. Electrical resistivity compared to the undoped film has been found to increase on Al doping.

Mukherjee, Ramnayan; Prajapati, C. S.; Sahay, P. P.

2014-09-01

127

Thin film concentrator panel development  

NASA Technical Reports Server (NTRS)

The development and testing of a rigid panel concept that utilizes a thin film reflective surface for application to a low-cost point-focusing solar concentrator is discussed. It is shown that a thin film reflective surface is acceptable for use on solar concentrators, including 1500 F applications. Additionally, it is shown that a formed steel sheet substrate is a good choice for concentrator panels. The panel has good optical properties, acceptable forming tolerances, environmentally resistant substrate and stiffeners, and adaptability to low to mass production rates. Computer simulations of the concentrator optics were run using the selected reflector panel design. Experimentally determined values for reflector surface specularity and reflectivity along with dimensional data were used in the analysis. The simulations provided intercept factor and net energy into the aperture as a function of aperture size for different surface errors and pointing errors. Point source and Sun source optical tests were also performed.

Zimmerman, D. K.

1982-01-01

128

Pulsed laser deposition of high Tc superconducting thin films: Present and future  

SciTech Connect

Pulsed laser deposition (PLD) has been widely used for deposition of high {Tc} superconducting thin films, and has been approved as one of the best physical vapor techniques to prepare the films. The most important advantage of this technique is stoichiometric deposition, namely the films could be made with the same composition of the targets. Utilized PLD, not only thin films but also multilayers and superlattices of high {Tc} superconductors have been fabricated. In this paper, the performance of the technique will be reviewed, and the future will be speculated.

Wu, X.D.; Muenchausen, R.E.; Foltyn, S.; Estler, R.C.; Dye, R.C.; Garcia, A.R.; Nogar, N.S. (Los Alamos National Lab., NM (USA)); Venkatesan, T.; Chang, C.C.; Ramesh, R.; Hwang, M.; Nazar, L.; Wilkens, B.; Schwarz, S.A.; Ravi, R.T.; Barner, J.B.; England, P.; Rogers, C.T.; Tarascon, J.M. (Bellcore, Red Bank, NJ (USA)); Inam, A.; Xi, X.X.; Li, Q. (Rutgers--the State Univ., Piscataway, NJ (USA). Dept. of Physics and

1990-01-01

129

Microstructural characterization in nanocrystalline ceramic thin films  

Microsoft Academic Search

The primary objective of this research is to investigate the effects of process variables on microstructure in several fluoride and oxide thin films prepared by vapor deposition, in order to predict the properties and behaviors of nanocrystalline thin film materials. There are three distinct stages of this research. The first stage focuses on measuring of the porosity in polycrystalline thin

Hakkwan Kim

2008-01-01

130

The Transition Temperature of a Thin Type II Superconductor in Contact with a Magnetic Metal.  

National Technical Information Service (NTIS)

Results of the dependence of the superconducting transition temperature on electronic mean free path in a thin alloy superconductor in contact with a ferromagnetic material are in agreement with the predictions of the linearized Ginzburg-Landau theory. (A...

R. P. Groff, R. D. Parks

1966-01-01

131

Preparation of thin ceramic films via an aqueous solution route  

DOEpatents

A new chemical method of forming thin ceramic films has been developed. An aqueous solution of metal nitrates or other soluble metal salts and a low molecular weight amino acid is coated onto a substrate and pyrolyzed. The amino acid serves to prevent precipitation of individual solution components, forming a very viscous, glass-like material as excess water is evaporated. Using metal nitrates and glycine, the method has been demonstrated for zirconia with various levels of yttria stabilization, for lanthanum-strontium chromites, and for yttrium-barium-copper oxide superconductors on various substrates.

Pederson, Larry R. (Kennewick, WA); Chick, Lawrence A. (Richland, WA); Exarhos, Gregory J. (Richland, WA)

1989-01-01

132

High-Temperature-Superconductor Films In Microwave Circuits  

NASA Technical Reports Server (NTRS)

Report discusses recent developments in continuing research on fabrication and characterization of thin films of high-temperature superconducting material and incorporation of such films into microwave circuits. Research motivated by prospect of exploiting superconductivity to reduce electrical losses and thereby enhancing performance of such critical microwave components as ring resonators, filters, transmission lines, phase shifters, and feed lines in phased-array antennas.

Bhasin, K. B.; Warner, J. D.; Romanofsky, R. R.; Heinen, V. O.; Chorey, C. M.

1993-01-01

133

Zinc oxide thin film acoustic sensor  

SciTech Connect

This paper reports the implementation of (750 nm) thickness of Zinc Oxide (ZnO) thin film for the piezoelectric pressure sensors. The film was prepared and deposited employing the spray pyrolysis technique. XRD results show that the growth preferred orientation is the (002) plane. A polycrystalline thin film (close to mono crystallite like) was obtained. Depending on the Scanning Electron Microscopy photogram, the film homogeneity and thickness were shown. The resonance frequency measured (about 19 kHz) and the damping coefficient was calculated and its value was found to be about (2.5538), the thin film be haves as homogeneous for under and over damped. The thin film pressure sensing was approximately exponentially related with frequency, the thin film was observed to has a good response for mechanical stresses also it is a good material for the piezoelectric properties.

Mohammed, Ali Jasim; Salih, Wafaa Mahdi; Hassan, Marwa Abdul Muhsien; Nusseif, Asmaa Deiaa; Kadhum, Haider Abdullah [Department of Physics , College of Science, Al-Mustansiriyah University, Baghdad (Iraq); Mansour, Hazim Louis [Department of Physics , College of Education, Al-Mustansiriyah University, Baghdad (Iraq)

2013-12-16

134

Zinc oxide thin film acoustic sensor  

NASA Astrophysics Data System (ADS)

This paper reports the implementation of (750 nm) thickness of Zinc Oxide (ZnO) thin film for the piezoelectric pressure sensors. The film was prepared and deposited employing the spray pyrolysis technique. XRD results show that the growth preferred orientation is the (002) plane. A polycrystalline thin film (close to mono crystallite like) was obtained. Depending on the Scanning Electron Microscopy photogram, the film homogeneity and thickness were shown. The resonance frequency measured (about 19 kHz) and the damping coefficient was calculated and its value was found to be about (2.5538), the thin film be haves as homogeneous for under and over damped. The thin film pressure sensing was approximately exponentially related with frequency, the thin film was observed to has a good response for mechanical stresses also it is a good material for the piezoelectric properties.

Mohammed, Ali Jasim; Salih, Wafaa Mahdi; Hassan, Marwa Abdul Muhsien; Mansour, Hazim Louis; Nusseif, Asmaa Deiaa; Kadhum, Haider Abdullah

2013-12-01

135

Hardness enhancement in nanocrystalline tantalum thin films  

SciTech Connect

Nanocrystalline tantalum thin film was prepared by radio frequency magnetron sputtering on a glass substrate. Structure and mechanical properties of the as-deposited thin film were investigated by X-ray diffraction, transmission electron microscopy, and nanoindentation. The salient feature in the present tantalum thin film with a grain size of 76.5 nm is the remarkable enhancement of hardness, about one order of magnitude higher than that of bulk coarse-grained tantalum.

Nieh, Tai-Gang [ORNL; Yang, Bing [ORNL; Zhang, Ming [ORNL; Chu, Jinn P [Taiwan National Ocean University

2006-01-01

136

Doping in zinc oxide thin films  

Microsoft Academic Search

Doping in zinc oxide (ZnO) thin films is discussed in this dissertation. The optimizations of undoped ZnO thin film growth using molecular-beam epitaxy (MBE) are discussed. The effect of the oxygen ECR plasma power on the growth rate, structural, electrical, and optical properties of the ZnO thin films were studied. It was found that larger ECR power leads to higher

Zheng Yang

2009-01-01

137

Method of producing amorphous thin films  

DOEpatents

Disclosed is a method of producing thin films by sintering which comprises: a. coating a substrate with a thin film of an inorganic glass forming parulate material possessing the capability of being sintered, and b. irridiating said thin film of said particulate material with a laser beam of sufficient power to cause sintering of said material below the temperature of liquidus thereof. Also disclosed is the article produced by the method claimed.

Brusasco, Raymond M. (Livermore, CA)

1992-01-01

138

A thin film nitinol heart valve.  

PubMed

In order to create a less thrombogenic heart valve with improved longevity, a prosthetic heart valve was developed using thin film nitinol (NiTi). A "butterfly" valve was constructed using a single, elliptical piece of thin film NiTi and a scaffold made from Teflon tubing and NiTi wire. Flow tests and pressure readings across the valve were performed in vitro in a pulsatile flow loop. Bio-corrosion experiments were conducted on untreated and passivated thin film nitinol. To determine the material's in vivo biocompatibility, thin film nitinol was implanted in pigs using stents covered with thin film NiTi. Flow rates and pressure tracings across the valve were comparable to those through a commercially available 19 mm Perimount Edwards tissue valve. No signs of corrosion were present on thin film nitinol samples after immersion in Hank's solution for one month. Finally, organ and tissue samples explanted from four pigs at 2, 3, 4, and 6 weeks after thin film NiTi implantation appeared without disease, and the thin film nitinol itself was without thrombus formation. Although long term testing is still necessary, thin film NiTi may be very well suited for use in artificial heart valves. PMID:16438227

Stepan, Lenka L; Levi, Daniel S; Carman, Gregory P

2005-11-01

139

Transport of thin superconducting films and multilayer heterostructure made by Atomic layer deposition  

NASA Astrophysics Data System (ADS)

We report the use of atomic layer deposition (ALD) to synthesize thin superconducting films and multilayer superconductor-insulator (S-I) heterostructures. The ALD technique applied to superconducting films opens the way for a variety of applications, including improving the performance and decreasing the cost of high energy particle accelerators, superconducting wires for energy storage, and bolometers for radiation detection. Furthermore, the atomic-scale thickness control afforded by ALD enables the study of superconductivity and associated phenomena in homogeneous layers in the ultra-thin film limit. In this respect, we will present results of ALD-grown transition metal-based superconductors, including nitrides, carbides, and silicides of niobium, nitrides of molybdenum and titanium, and Nb1-xTixN/AlN-based S-I heterostructures. Transport measurement for various composition and film thicknesses will be presented.

Proslier, Thomas; Klug, Jeffrey; Groll, Nickolas; Becker, Nicholas; Glatz, Andreas; Vinokur, Valerii; Pellin, Michael; Baturina, Tatyana; Elam, Jeffrey; Zasadzsinki, John

2013-03-01

140

Thin film fuel cell electrodes.  

NASA Technical Reports Server (NTRS)

Earlier work shows that fuel cell electrodes prepared by sputtering thin films of platinum on porous vycor substrates avoid diffusion limitations even at high current densities. The presented study shows that the specific activity of sputtered platinum is not unusually high. Performance limitations are found to be controlled by physical processes, even at low loadings. Catalyst activity is strongly influenced by platinum sputtering parameters, which seemingly change the surface area of the catalyst layer. The use of porous nickel as a substrate shows that pore size of the substrate is an important parameter. It is noted that electrode performance increases with increasing loading for catalyst layers up to two microns thick, thus showing the physical properties of the sputtered layer to be different from platinum foil. Electrode performance is also sensitive to changing differential pressure across the electrode. The application of sputtered catalyst layers to fuel cell matrices for the purpose of obtaining thin total cells appears feasible.

Asher, W. J.; Batzold, J. S.

1972-01-01

141

Thin film solar energy collector  

DOEpatents

A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

Aykan, Kamran (Monmouth Beach, NJ); Farrauto, Robert J. (Westfield, NJ); Jefferson, Clinton F. (Millburn, NJ); Lanam, Richard D. (Westfield, NJ)

1983-11-22

142

thin films by thermal annealing  

NASA Astrophysics Data System (ADS)

La2/3Ba1/3MnO3:Ag0.04 (LBMO:Ag0.04) thin films were prepared on single crystalline (001)-orientated LaAlO3 substrates by pulsed laser deposition technique. Thermal annealing with temperatures of 780, 800 and 820 °C has been investigated to improve electrical properties of the films. All the samples are shown along the (00 l) orientation in rhombohedral structure with space group. With thermal annealing temperature increasing, insulator-metal transition temperature ( T p) and resistivity at T p () of the epilayer reach optimal value of 288 K and 0.03 ?·cm, respectively. The electrical properties improvement of the LBMO:Ag0.04 films is due to an improved film crystallization, oxygen balance and photon scattering suppression. The fitting curves show that the region of ferro-magnetic metallic (FM, T < T p) is fitted with grain/domain boundary, electron-electron and magnon scattering mechanism, as well as the region of para-magnetic insulating (PI, T > T p) is fitted with adiabatic small polaron hopping mechanism.

Liu, Xiang; Yin, Xue-Peng; Chen, Qing-Ming; Zhang, Hui; Zhang, Shao-Chun

2014-09-01

143

Atomic structure of GdBa2Cu3O7 superconductor thin films on NdGaO3(0 0 1)Probed by X-ray standing waves and photoelectron spectroscopy  

NASA Astrophysics Data System (ADS)

We characterized the structure of GdBa 2Cu 3O 7thin films grown on NdGaO 3(0 0 1) substrates using X-ray standing waves combined with photoelectron spectroscopy. The O 1 s and Cu 2 p core-level spectra display components that exhibit distinct X-ray standing wave modulations, which we identify as arising from the well-ordered (intrinsic) parts of the oxide films, but also contain nearly unmodulated components arising from reacted, degraded phases (non-intrinsic). The large mean-free paths of high kinetic-energy photoelectrons permits, in addition, the detection of the Nd and Ga atoms near the buried interface below a 3.5-nm film. Our measurements reveal an essentially bulk-terminated NdGaO 3 surface at the interface. By considering a pseudomorphically strained, orthorhombic Y123 structure for the 3.5-nm film, we find that our X-ray standing wave data are consistent with an interface composed of CuO-NdO planes, where the Cu-Nd distances are determined to be 0.18 nm. The analysis rules out the possibility for the film to start its stacking with a BaO plane. The X-ray standing wave measurement for the GdBa 2Cu 3O 7 valence band yields results nearly identical to the intrinsic part of the Cu 2 p core level and therefore confirms the major contribution of Cu 3 d to the valence band in high-temperature cuprates. For thicker films, the standing wave analysis on a 17.5-nm sample indicates that the film is partially relaxed, in good agreement with the previous X-ray diffraction results. Repeating the measurements at 60 K suggests that the in-plane lattice mismatch between the film and substrate increases with decreasing temperature.

Lee, T.-L.; Warren, S.; Cao, L. X.; Thie?, S.; Cowie, B. C. C.; Zegenhagen, J.

2005-07-01

144

Brownian Motion of Dislocations in Thin Films  

SciTech Connect

The motion of edge dislocations in a single monolayer film of Cu on Ru(0001) was studied by time-resolved scanning tunneling microscopy. The dislocations were observed to make rapid 1D random walks in the film. This dislocation motion is attributed to the equilibrium thermal exchange of atoms between the solid film and the adatom gas covering the film. These results highlight a fundamental difference between the dynamics of dislocations in thin films and the bulk, which is in principle important in understanding the mechanical properties of thin films. {copyright} {ital 1997} {ital The American Physical Society}

Schmid, A.; Bartelt, N.; Hamilton, J.; Carter, C.; Hwang, R. [Sandia National Laboratories, Livermore, California 94551-0969 (United States)] [Sandia National Laboratories, Livermore, California 94551-0969 (United States)

1997-05-01

145

Growth Optimization of Zinc Phthalocyanine Thin Films fo High Performance Thin Film Transistor  

NASA Astrophysics Data System (ADS)

The morphology of thermally evaporated zinc phthalocynine (ZnPc) organic thin films were engineered for obtaining high performance organic thin film transistor(OTFT) by varying substrate temperature and fixed deposition rate 0.1 Å/sec. ZnPc thin films were characterized by X-ray diffraction (XRD) and atomic force microscopy. The output characteristic of organic thin film transistor shows the highest mobility in the device with the thin film grown at 90 °C by reducing the effect of grain boundaries.

Yadav, Sarita; Ghosh, Subhasis

2011-07-01

146

Preface: Thin films of molecular organic materials  

Microsoft Academic Search

This special issue is devoted to thin films of molecular organic materials and its aim is to assemble numerous different aspects of this topic in order to reach a wide scientific audience. Under the term 'thin films', structures with thicknesses spanning from one monolayer or less up to several micrometers are included. In order to narrow down this relaxed definition

J. Fraxedas

2008-01-01

147

Laser processing for thin-film photovoltaics  

Microsoft Academic Search

Over the past decade major advances have occurred in the field of thin- film photovoltaics (PV) with many of them a direct consequence of the application of laser processing. Improved cell efficiencies have been achieved in crystalline and polycrystalline Si, in hydrogenated amorphous silicon, and in two polycrystalline thin-film materials. The use of lasers in photovoltaics includes laser hole drilling

Alvin D. Compaan

1995-01-01

148

Water sorption in epoxy thin films  

Microsoft Academic Search

Moisture uptake and desorption experiments performed on both thick (order of millimeters) and thin (order of 10 ?m) free films of epoxies are presented. Supported thin films were prepared by spin coating and curing epoxies directly on cleaned glass slides. These latter samples were tested in a similar manner. Distinctive nonFickian behavior was observed. Equilibrium uptake is achieved via a

MICHAEL G. MCMASTER; DAVID S. SOANE

1989-01-01

149

Coalescence and percolation in thin metal films  

Microsoft Academic Search

Metals thermally evaporated onto warm insulating substrates evolve to the thin-film state via the morphological sequence: compact islands, elongated islands, percolation, hole filling, and finally the thin-film state. The coverage at which the metal percolates (pc) is often considerably higher than that predicted by percolation models, such as inverse swiss cheese or lattice percolation. Using a simple continuum model, we

X. Yu; P. M. Duxbury; G. Jeffers; M. A. Dubson

1991-01-01

150

Thin films of mixed metal compounds  

DOEpatents

A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

Mickelsen, Reid A. (Bellevue, WA); Chen, Wen S. (Seattle, WA)

1985-01-01

151

Magnetic Structure of Engineered Multiferroic Thin Films  

Microsoft Academic Search

The intriguing properties of multiferroics, i.e., materials exhibiting the coexistence of magnetism and ferroelectricity, have stimulated intense research interest in recent years. From the viewpoint of practical applications, one needs to exploit the thin film architectures of multiferroic materials. However, fewer studies have addressed the magnetic structures of multiferroic thin films. I will present recent experimental works on two multiferroic

Xianglin Ke

2011-01-01

152

Thin film shape memory alloy microactuators  

Microsoft Academic Search

Thin film shape memory alloys (SMAs) have the potential to become a primary actuating mechanism for mechanical devices with dimensions in the micron-to-millimeter range requiring large forces over long displacements. The work output per volume of thin film SMA microactuators exceeds that of other microactuation mechanisms such as electrostatic, magnetic, thermal bimorph, piezoelectric, and thermopneumatic, and it is possible to

P. Krulevitch; A. P. Lee; P. B. Ramsey; J. C. Trevino; M. A. Northrup

1996-01-01

153

Multiferroics: progress and prospects in thin films  

Microsoft Academic Search

Multiferroic materials, which show simultaneous ferroelectric and magnetic ordering, exhibit unusual physical properties - and in turn promise new device applications - as a result of the coupling between their dual order parameters. We review recent progress in the growth, characterization and understanding of thin-film multiferroics. The availability of high-quality thin-film multiferroics makes it easier to tailor their properties through

R. Ramesh; Nicola A. Spaldin

2007-01-01

154

Electrostatic thin film chemical and biological sensor  

DOEpatents

A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

Prelas, Mark A. (Columbia, MO); Ghosh, Tushar K. (Columbia, MO); Tompson, Jr., Robert V. (Columbia, MO); Viswanath, Dabir (Columbia, MO); Loyalka, Sudarshan K. (Columbia, MO)

2010-01-19

155

A monolithic thin film electrochromic window  

NASA Astrophysics Data System (ADS)

Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community.

Goldner, R. B.; Arntz, F. O.; Berera, G.; Haas, T. E.; Wong, K. K.; Wei, G.; Yu, P. C.

156

Cellulose triacetate, thin film dielectric capacitor  

NASA Technical Reports Server (NTRS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S. (inventor); Jow, T. Richard (inventor)

1995-01-01

157

Cellulose triacetate, thin film dielectric capacitor  

NASA Technical Reports Server (NTRS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S. (inventor); Jow, T. Richard (inventor)

1993-01-01

158

Thin Dielectric Films Containing Tb3+ Ions For Application In Thin Film Solar Cells  

Microsoft Academic Search

Thin transparent dielectric films containing Tb3+ are developed for application as spectral converters of the solar spectrum in thin film silicon solar cells. The results on the deposition and characterization of thin SiO2 and Al2O3 films containing Tb3+ ions are presented. The films are prepared by RF magnetron co-sputtering, a well established technique for large area coatings. Photoluminescence (PL) is

M. Sendova-Vassileva; K. Baumgartner; O. Angelov; B. Holländer; D. Dimova-Malmovska; R. Carius

2010-01-01

159

Electrical conduction of thin bismuth films  

Microsoft Academic Search

The electrical resistivity of thin bismuth films, thermally evaporated onto freshly cleaved mica and glass substrates has\\u000a been studied. Measurements were carried out in a wide range of temperatures and thicknesses. The data measured for thicker\\u000a films were fitted to aFuchs-Sondheimer model withp=0, while the abrupt rise of resistivity for very thin films is described assuming a tunnelling mechanism for

A. H. Abou El Ela; S. Mahmoud; M. A. Mahmoud

1982-01-01

160

Thin film limits for Ginzburg--Landau with strong applied magnetic fields  

E-print Network

In this work, we study thin-film limits of the full three-dimensional Ginzburg-Landau model for a superconductor in an applied magnetic field oriented obliquely to the film surface. We obtain Gamma-convergence results in several regimes, determined by the asymptotic ratio between the magnitude of the parallel applied magnetic field and the thickness of the film. Depending on the regime, we show that there may be a decrease in the density of Cooper pairs. We also show that in the case of variable thickness of the film, its geometry will affect the effective applied magnetic field, thus influencing the position of vortices.

Stan Alama; Lia Bronsard; Bernardo Galvão-Sousa

2009-06-30

161

Dynamic delamination of patterned thin films  

NASA Astrophysics Data System (ADS)

We investigate laser-induced dynamic delamination of a patterned thin film on a substrate. Controlled delamination results from our insertion of a weak adhesion region beneath the film. The inertial forces acting on the weakly bonded portion of the film lead to stable propagation of a crack along the film/substrate interface. Through a simple energy balance, we extract the critical energy for interfacial failure, a quantity that is difficult and sometimes impossible to characterize by more conventional methods for many thin film/substrate combinations.

Kandula, Soma S. V.; Tran, Phuong; Geubelle, Philippe H.; Sottos, Nancy R.

2008-12-01

162

Thin film bioreactors in space.  

PubMed

Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology. PMID:11537324

Hughes-Fulford, M; Scheld, H W

1989-01-01

163

Primary research efforts on exploring the commercial possibilities of thin film growth and materials purification in space  

NASA Technical Reports Server (NTRS)

The progress made on research programs in the 1987 to 1988 year is reported. The research is aimed at producing thin film semiconductors and superconductor materials in space. Sophisticated vacuum chambers and equipment were attained for the epitaxial thin film growth of semiconductors, metals and superconductors. In order to grow the best possible epitaxial films at the lowest possible temperatures on earth, materials are being isoelectronically doped during growth. It was found that isoelectrically doped film shows the highest mobility in comparison with films grown at optimal temperatures. Success was also attained in growing epitaxial films of InSb on sapphire which show promise for infrared sensitive devices in the III-V semiconductor system.

1989-01-01

164

Optical properties of transparent conducting oxide sculptured thin films for application in thin film silicon photovoltaics  

Microsoft Academic Search

Oxide thin films serving dual roles of transparent conductor and optical filter have been proposed on the basis of the sculptured thin film (STF) concept. This concept entails variations in the polar and azimuthal angles (?, ?) of the deposited flux with respect to the substrate normal, that are performed step-wise or continuously during film growth in order to achieve

N. J. Podraza; Chi Chen; J. M. Flores; D. Sainju; I. An; G. M. Ferreira; C. R. Wronski; M. W. Horn; R. Messier; R. W. Collins

2005-01-01

165

VUV thin films, chapter 7  

NASA Technical Reports Server (NTRS)

The application of thin film technology to the vacuum ultraviolet (VUV) wavelength region from 120 nm to 230 nm has not been fully exploited in the past because of absorption effects which complicate the accurate determination of the optical functions of dielectric materials. The problem therefore reduces to that of determining the real and imaginary parts of a complex optical function, namely the frequency dependent refractive index n and extinction coefficient k. We discuss techniques for the inverse retrieval of n and k for dielectric materials at VUV wavelengths from measurements of their reflectance and transmittance. Suitable substrate and film materials are identified for application in the VUV. Such applications include coatings for the fabrication of narrow and broadband filters and beamsplitters. The availability of such devices open the VUV regime to high resolution photometry, interferometry and polarimetry both for space based and laboratory applications. This chapter deals with the optics of absorbing multilayers, the determination of the optical functions for several useful materials, and the design of VUV multilayer stacks as applied to the design of narrow and broadband reflection and transmission filters and beamsplitters. Experimental techniques are discussed briefly, and several examples of the optical functions derived for selected materials are presented.

Zukic, Muamer; Torr, Douglas G.

1993-01-01

166

Deposition and characterization of thin HTS and magnetic perovskite films  

NASA Astrophysics Data System (ADS)

The in-situ growth and physical properties were investigated of thin films and bilayers of high-temperature superconductors (HTS) YBa2Cu3O7 (YBCO) and ferromagnetic (FM) manganites La0.7Sr0.3MnO3 (LSMO) and La0.7Ca0.3MnO3 (LCMO) with thicknesses of several tens of nm obtained by magnetron sputtering. Similar twin structures were observed by an optical microscope in areas on the LaAlO3 substrate surface void of films, in areas containing YBCO, in LSMO films, and in YBCO/LCMO bilayers, although the main spatial period of the twin structure seemed to be slightly different in the areas containing the LSMO film. The resistance (and its temperature dependence) of the LCMO films strongly depends on the annealing conditions. The resistance of the LSMO and LCMO films grown on Al2O3 substrates decreased as the temperature (T) was increased in the lower and higher temperature ranges, and increased as T was increased at medium temperatures.

Blagoev, B. S.; Gostev, I. G.; Nurgaliev, T. K.; Strbik, V.; Bineva, I. E.; Uspenskaya, L.; Mateev, E. S.; Neshkov, L.; Dobro?ka, E.; Chromik, Š.

2014-05-01

167

Macro stress mapping on thin film buckling  

SciTech Connect

Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been done to develop mechanical models but only a few experimental work has been done on this subject to support these theoretical approaches and nothing concerning local stress measurement mainly because of the small dimension of the buckling (few 10th mm). This paper deals with the application of micro beam X-ray diffraction available on synchrotron radiation sources for stress mapping analysis of gold thin film buckling.

Goudeau, P.; Villain, P.; Renault, P.-O.; Tamura, N.; Celestre, R.S.; Padmore, H.A.

2002-11-06

168

Aging phenomena in polystyrene thin films  

E-print Network

The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change in thickness and dielectric permittivity, respectively. In thin films, the thickness depends on thermal history of aging even above the glass transition. Memory and `rejuvenation' effects are also observed in the thin films.

Koji Fukao; Hiroki Koizumi

2008-01-05

169

Propagation of Rayleigh waves in thin films  

NASA Astrophysics Data System (ADS)

With the advent of thin film technology and more recently its applications in microelectronics and control of surface properties, the interest in mechanical properties of thin films has grown tremendously. Mechanical defects such as creep, fracture and adhesion loss, play a very important role in physical instabilities of thin film materials. An acoustic microscope has been built to study mechanical properties of thin-films. The microscope operates at a nominal frequency of 50 MHz. Rayleigh surface waves velocities on the surface of film-substrate systems were measured from V(z) curves generated by the acoustic microscope. V(z) curves are produced from interference between the Rayleigh surface wave and the specularly reflected waves. Technologically important materials, non-stoichiometric titanium nitride (TiN x) films and diamond films, were fabricated by using magnetron plasma deposition and hot filament chemical vapor deposition (HFCVD) on Si (100) and Si (111) substrates. Spectra from XPS (X-ray Photoelectron Spectroscopy) were used to determine the chemical composition of the films and SEM (Scanning Electron Microscope) micrographs were taken to study the morphology of the films. Rayleigh surface wave velocity measurements on TiN x films show a sharp increase in velocity at x = 0.7. A comparison with the phase diagram of TiN x suggests that the sharp increase in velocity might be due to a crystal structural transition from tetragonal ?-Ti2N to fcc ?-TiN.

Ananda, Agus A.

170

Permanent laser conditioning of thin film optical materials  

DOEpatents

The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

1995-12-05

171

Sensing using nanostructured metal oxide thin films  

NASA Astrophysics Data System (ADS)

Metal oxides gas sensing properties particularly for In IIO 3 and ZnO nanostructures and nanostructured thin films are reviewed. Fabrication methods for these most commonly used metal oxides are presented, followed by a study on how growth techniques lead to nanostructures and nanostructured polycrystalline films with surface features of nanometer scale for film thickness bellow 1?m. The study continues with a discussion on how, a broad range of morphological parameters, affect the thin film response to various gases. After an overview, the study focus on thin films prepared by reactive dc magnetron sputtering and pulsed laser deposition in different growth conditions. In IIO 3 and ZnO thin films prepared for ozone sensing exhibit resistivity changes of five to eight orders of magnitude at room temperature after exposure to UV light and subsequent ozone treatment. Structural properties, i.e., crystallinity and microstructure investigated by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) are studied. The nanostructure and nanostructured surfaces are highly controlled by the deposition parameters, which, control the transport properties, and thus the sensing characteristics as measured by conductometric techniques. Analyses on the sensing response of nanostructures and nanostructured In IIO 3 and ZnO films for different gases are presented. Experiments on Surface Acoustic Wave (SAW) devices based on In IIO 3 and ZnO thin films fabricated on LiNbO3 substrates indicate the capability of achieving sensing levels in the low ppb range.

Kiriakidis, G.; Dovinos, D.; Suchea, M.

2006-10-01

172

Analysis of Hydrogen Isotopes in Thin Films.  

National Technical Information Service (NTIS)

Mass spectrometer modifications made for high resolution analysis of hydrogen isotopes outgassed from occluder thin films are described. The electronic modifications made to the source, magnet power supply, and scanning circuits have provided increased pr...

J. O. Humphries, T. K. Mehrhoff

1976-01-01

173

Thin film production method and apparatus  

DOEpatents

A method for forming a thin film material which comprises depositing solid particles from a flowing suspension or aerosol onto a filter and next adhering the solid particles to a second substrate using an adhesive.

Loutfy, Raouf O. (Tucson, AZ); Moravsky, Alexander P. (Tucson, AZ); Hassen, Charles N. (Tucson, AZ)

2010-08-10

174

Thin films for geothermal sensing: Final report  

SciTech Connect

The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)

Not Available

1987-09-01

175

Visible spectrometer utilizing organic thin film absorption  

E-print Network

In this thesis, I modeled and developed a spectrometer for the visible wavelength spectrum, based on absorption characteristics of organic thin films. The device uses fundamental principles of linear algebra to reconstruct ...

Tiefenbruck, Laura C. (Laura Christine)

2004-01-01

176

Synthesis of periodic mesoporous silica thin films  

Microsoft Academic Search

We have synthesized periodic mesoporous silica thin films from homogeneous solutions. To synthesize the films, a thin layer of a pH 7 micellar coating solution that contains TMOS (tetramethoxysilane) is dip or spin-coated onto Si wafers, borosilicate glass, or quartz substrates. NH3 gas is diffused into the solution and causes rapid hydrolysis and condensation of the TMOS and the formation

M. T. Anderson; J. E. Martin; J. G. Odinek; P. Newcomer

1996-01-01

177

Thin-film interference Aditya Joshi  

E-print Network

, y, z, t) = Eo sin(kx - t)^y (1) It is worth noting what all the symbols stand for. · Eo is the peak of two important effects that will be explained presently. Figure 1: A thin film of oil floating on water that is incident upon the interface between air (na = 1) and a thin film of oil of thickness `t'(for this oil

Packard, Richard E.

178

Thin-film reliability and engineering overview  

NASA Technical Reports Server (NTRS)

The reliability and engineering technology base required for thin film solar energy conversions modules is discussed. The emphasis is on the integration of amorphous silicon cells into power modules. The effort is being coordinated with SERI's thin film cell research activities as part of DOE's Amorphous Silicon Program. Program concentration is on temperature humidity reliability research, glass breaking strength research, point defect system analysis, hot spot heating assessment, and electrical measurements technology.

Ross, R. G., Jr.

1984-01-01

179

Multilayer Thin Film Sensors for Damage Diagnostics  

NASA Astrophysics Data System (ADS)

The new innovative approach to damage diagnostics within the production and maintenance/servicing procedures in industry is proposed. It is based on the real-time multiscale monitoring of the smart-designed multilayer thin film sensors of fatigue damage with the standard electrical input/output interfaces which can be connected to the embedded and on-board computers. The multilayer thin film sensors supply information about the actual unpredictable deformation damage, actual fatigue life, strain localization places, damage spreading, etc.

Protasov, A. G.; Gordienko, Y. G.; Zasimchuk, E. E.

2006-03-01

180

Bi-Sr-Ca-Cu-O thin films grown by flash evaporation and pulsed laser deposition  

E-print Network

hours (c) Annealed at 825oC for 3 hours??????? 52 19 (a) SEM micrograph of as-grown film, grown at 725oC (b) AFM image of the above film (c) AFM image of the film, annealed at 835oC for 1 hour??????????????????????... 54 20 AFM analysis of BSCCO thin..., and has not yet been achieved. These superconductors have a crystal structure commonly known as the modified perovskite structure. The family of perovskite materials has the generic formula ABO3. The designation ?perovskite? originates from the mineral Ca...

Ganapathy Subramanian, Santhana

2004-09-30

181

Thin-Film Nanocapacitor and Its Characterization  

ERIC Educational Resources Information Center

An undergraduate thin-film nanotechnology laboratory was designed. Nanocapacitors were fabricated on silicon substrates by sputter deposition. A mask was designed to form the shape of the capacitor and its electrodes. Thin metal layers of Au with a 80 nm thickness were deposited and used as two infinitely large parallel plates for a capacitor.…

Hunter, David N.; Pickering, Shawn L.; Jia, Dongdong

2007-01-01

182

RF surface resistance of YBa2Cu3O(7-x) thin films  

NASA Technical Reports Server (NTRS)

The excitement engendered by the discovery of the new T sub c oxide superconductors has led to much speculation about practical applications of thin films of these materials in digital and analog electronic devices. Most of these envisioned applications involve high frequency signals for which a detailed knowledge of the surface impedance of the novel superconductors is very important. We have measured the surface resistance of thin films of YBaCuO in the frequency range 0.5 less than f less than 17 GHz using a stripline-resonator method. The stripline procedure also was used to measure the surface resistance of high quality gold and aluminum films; the resistance values obtained agree with values predicted from the measured dc resistance using the Pippard formalism for the anomalous skin effect. The YBaCuO were produced by a multilayer deposition process. The films are formed by e-beam evaporation of 24 layers of Y, Ba, and Cu. Films with the highest transition temperature were obtained using yttria-stabilized zirconia (YSZ) substrates. After deposition, the films are transferred to a furnace where they are annealed in flowing O2 at 850 C for 2h. The furnace then is turned off and allowed to cool to 100 C in about 16 h. Auger profiling of the films made by this process shows that the concentrations of Y, Ba, Cu, and O are uniform to within 1 percent throughout the thickness of the film.

1988-01-01

183

Electrical resistivity of thin bismuth films  

Microsoft Academic Search

The thickness dependence of electrical resistivity of thin bismuth films deposited on to glass substrates has been studied in the temperature range 77 to 350 K. The structural studies show that films are polycrystalline with grain size increasing with thickness. The electrical resistivity decreases with increasing temperature. This type of temperature dependence of electrical resistivity arises due to the competition

A. Kumar; O. P. Katyal

1990-01-01

184

Stress and grain growth in thin films  

Microsoft Academic Search

The mechanical properties of polycrystalline thin films with thickness of 1 ?m or less depend strongly on the grain geometry, the grain size, and the way in which the crystallographic orientations of the grains are distributed. Grain growth during film formation or during post-deposition annealing can play a dominant role in defining these microstructural characteristics, and therefore, the mechanical properties

Carl V. Thompson; Roland Carel

1996-01-01

185

Thin-film distributed-feedback lasers  

Microsoft Academic Search

Progress in fabricating thin-film distributed feedback (DFB) lasers is discussed. A DFB structure can be produced by inducing a periodic spatial variation of the refractive index or of the gain constant of the laser medium. As an example, a DFB dye laser in a gelatin film was constructed. Ideas borrowed from dye laser experiments are applied to the development of

C. V. Shank

1975-01-01

186

On Spray Pyrolyzed Nickel Oxide Thin Films  

Microsoft Academic Search

Nickel oxide thin films have been prepared by a simple and inexpensive spray pyrolysis technique and have been studied for their structural, optical and electrical properties. The films consist of NiO (cubic) phase. The direct band gap energy is estimated to be 3.4 eV. Room temperature electrical resistivity is of the order of 106 W-cm.

L. D. Kadam; C. H. Bhosale; P. S. Patil

1997-01-01

187

Nanostructured mesoporous nickel oxide thin films  

Microsoft Academic Search

Nanostructured nickel oxide thin films were prepared by the pulsed laser ablation technique. The effects of annealing on the structural, morphological, electrical and optical properties are discussed. Phase imaging was used to examine the surface contaminants, adhesion and hardness and height imaging to evaluate the height profile of the films. Morphological investigations using atomic force microscopy and scanning electron microscopy

B. Sasi; K. G. Gopchandran

2007-01-01

188

Large grain gallium arsenide thin films  

SciTech Connect

Polycrystalline gallium arsenide films deposited on tungsten/graphite substrates have been used for the fabrication of thin film solar cells. Gallium arsenide films deposited on foreign substrates of 10 ..mu..m or less thickness exhibit, in most cases, pronounced shunting effects due to grain boundaries. MOS solar cells of 9 cm/sup 2/ area with an AMI efficiency of 8.5% and p/sup +//n/n/sup +/ homojunction solar cells of 1 cm/sup 2/ area with an AM1 efficiency of 8.8% have been prepared. However, in order to further improve the conversion efficiency before the development of effective passivation techniques, gallium arsenide films with large and uniform grain structure are necessary. The large grain gallium arsenide films have been prepared by using the arsine treatment of a thin layer of molten gallium on the substrate surface and the recrystallized germanium films on tungsten/graphite as substrates.

Chu, S.S.; Chen, W.J.; Chu, T.L.; Firouzi, H.; Han, Y.X.; Wang, Q.H.

1984-05-01

189

Atomic imaging in EBCO superconductor films by an X-ray holography system using a toroidally bent graphite analyzer.  

PubMed

X-ray fluorescence holography (XFH) is a new technique enabling the determination of the three-dimensional local atomic structure around a certain element. This method has been applied to analyze the local structure around Cu in 300 nm thin films of EuBa(2)Cu(3)O(7-delta) (EBCO) epitaxially grown on MgO (100) substrate, using the newest system for XFH measurement and high-brilliance synchrotron radiation at SPring-8. Here, the results of a study on the irradiation effect on the local atomic structure of EBCO superconductor with XFH measurements are presented. PMID:15968134

Sekioka, Tsuguhisa; Hayashi, Kouichi; Matsubara, Eiichiro; Takahashi, Yukio; Hayashi, Tetsutaro; Terasawa, Mititaka; Mitamura, Tohru; Iwase, Akihiro; Michikami, Osamu

2005-07-01

190

Polysilicon Super-Thin-Film Transistor (SFT)  

Microsoft Academic Search

N-channel MOS FET's have been fabricated in super-thin polysilicon film on quartz substrate. The thickness of the film had an important role in improving the electrical properties. Moreover, grain boundary passivation by the hydrogen from a plasma-SiN film has been developed to increase the field effect mobility. The field effect mobility is more than 20 cm2\\/V\\\\cdots at the polysilicon thickness

Hisao Hayashi; Takashi Noguchi; Takefumi Oshima

1984-01-01

191

Flexible Thin Metal Film Thermal Sensing System  

NASA Technical Reports Server (NTRS)

A flexible thin metal film thermal sensing system is provided. A thermally-conductive film made from a thermally-insulating material is doped with thermally-conductive material. At least one layer of electrically-conductive metal is deposited directly onto a surface of the thermally-conductive film. One or more devices are coupled to the layer(s) to measure an electrical characteristic associated therewith as an indication of temperature.

Thomsen, Donald Laurence (Inventor)

2012-01-01

192

Knudsen diffusion through thin fibrous films  

NASA Astrophysics Data System (ADS)

Variational upper and multiple scattering lower bounds on the Knudsen transport rates are applied to several slab geometries of finite thickness made up of parallel, randomly placed, overlapping long cylindrical fibers, one with fibers aligned perpendicular and a second with fibers parallel to the film edges. Estimates and rigorous error bounds are generated for various film thickness. Insight into collision paths useful for thin film vapor deposition, reactive matrix formation of composites, and gas membrane transport are obtained.

Li, Xiangning; Strieder, William C.

2007-06-01

193

Superconductor to insulator transitions in amorphous nanohoneycomb films  

NASA Astrophysics Data System (ADS)

Two dimensional electronic systems exhibit a wide variety of phenomena including the quantum Hall effect, weak and strong localization, and metal-insulator transitions, including the superconductor to insulator transition (SIT). In each case the possibility of a universal explanation, independent of the microscopic details of the system, has tantalized researchers. In some cases, such as the temperature dependence of the conductance of metal films, or the spacing of resistance plateaus in the Hall effect, universal behavior is without doubt. Universal explanations of the amorphous film SIT revolve around the dirty Boson model, in which the sharp rise in the resistance of a film at low temperature is due to the localization of Cooper pairs. The existence of long-lived Cooper pairs in an electrically insulating system, the central assumption of the model, has remained in doubt because some measurements support the assertion and others refute it. This thesis addresses this experimental dissonance by investigating the SITs of amorphous Bismuth films perforated with a regular nanohoneycomb (NHC) array of holes. The nanoscale perforations allow a direct measurement of phase coherent Cooper pairs with an applied magnetic field. On the insulating side of the disorder driven SIT the resistance as a function of magnetic field oscillates with a period, h/2eS, where S is the area of a unit cell of holes. The 2e period betrays the presence of localized Cooper pairs in an electrically insulating state. The magnetoresistance of weak superconducting films reveals several SITs which qualitatively resemble the disorder driven SIT. The behavior of these transitions borrows heavily from both sides of a dichotomy exhibited by different materials through their field driven SITs. NHC films show activated resistances and a large peak in the magnetoresistance, analogous to the more spectacular behavior of some materials. However, they also show a very weak, almost metallic, temperature dependence for a range of fields near the SIT, not unlike the metallic phase of unpatterned Bismuth and other materials. These results suggest that an underlying multiply connected geometry in ostensibly amorphous, unpatterned films may account for some of the range of material dependent behavior.

Stewart, M. D., Jr.

194

Glassy dynamics in thin films of polystyrene  

E-print Network

Glassy dynamics was investigated for thin films of atactic polystyrene by complex electric capacitance measurements using dielectric relaxation spectroscopy. During the isothermal aging process the real part of the electric capacitance increased with time, whereas the imaginary part decreased with time. It follows that the aging time dependences of real and imaginary parts of the electric capacitance were primarily associated with change in volume (film thickness) and dielectric permittivity, respectively. Further, dielectric permittivity showed memory and rejuvenation effects in a similar manner to those observed for poly(methyl methacrylate) thin films. On the other hand, volume did not show a strong rejuvenation effect.

Koji Fukao; Hiroki Koizumi

2008-01-05

195

Reactive gold thin films grown on iridium  

NASA Astrophysics Data System (ADS)

We report results of our studies on the dissociative adsorption of hydrogen on Au thin films grown epitaxially on Ir{1 1 1} surface, using nuclear reaction analysis. We found that H 2 dissociatively adsorbs on these Au{1 1 1} films. This feature can be contrasted to the well-known noble bulk Au surfaces, which do not dissociate hydrogen molecules. We attribute this to the local surface properties, e.g., electron localization (the narrowing of the s-band, the s-band center model), which can explain the unexpected high reactivity of a thin Au{1 1 1} film.

Okada, Michio; Ogura, Shouhei; Diño, Wilson Agerico; Wilde, Markus; Fukutani, Katsuyuki; Kasai, Toshio

2005-06-01

196

Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films  

DOEpatents

A method for preparing aerogel thin films by an ambient-pressure, continuous process. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

Brinker, Charles Jeffrey (Albuquerque, NM); Prakash, Sai Sivasankaran (Minneapolis, MN)

1999-01-01

197

Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films  

SciTech Connect

A method for preparing aerogel thin films by an ambient-pressure, continuous process is disclosed. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

Brinker, C.J.; Prakash, S.S.

1999-09-07

198

Adhesive transfer of thin viscoelastic films.  

PubMed

Micellar suspensions of acrylic diblock copolymers are excellent model materials for studying the adhesive transfer of viscoelastic solids. The micellar structure is maintained in films with a variety of thicknesses, giving films with a well-defined structure and viscoelastic character. Thin films were cast onto elastomeric silicone substrates from micellar suspensions in butanol, and the adhesive interactions between these coated elastomeric substrates and a rigid indenter were quantified. By controlling the adhesive properties of the film/indenter and film/substrate interfaces we were able to obtain very clean transfer of the film from the substrate to the portion of the glass indenter with which the film was in contact. Adhesive failure at the film/substrate interface occurs when the film/indenter interface is able to support an applied energy release rate that is sufficient to result in cavity nucleation at the film/substrate interface. Cavity formation is rapidly followed by delamination of the entire region under the indenter. The final stage in the transfer process involves the failure of the film that bridges the indenter and the elastomeric substrate. This film is remarkably robust and is extended to three times its original width prior to failure. Failure of this film occurs at the periphery of the indenter, giving a transferred film that conforms to the original contact area between the indenter and the coated substrate. PMID:15620300

Shull, Kenneth R; Martin, Elizabeth F; Drzal, Peter L; Hersam, Mark C; Markowitz, Alison R; McSwain, Rachel L

2005-01-01

199

Microscale damping using thin film active materials  

NASA Astrophysics Data System (ADS)

This paper focuses on understanding and developing a new approach to dampen MEMS structures using both experiments and analytical techniques. Thin film Nitinol and thin film Terfenol-D are evaluated as a damping solution to the micro scale damping problem. Stress induced twin boundary motion in Nitinol is used to passively dampen potentially damaging vibrations. Magnetic domain wall motion is used to passively dampen vibration in Terfenol-D. The thin films of Nitinol, Nitinol/Silicon laminates and Nitinol/Terfenol-D/Nickel laminates have been produced using a sputter deposition process and damping properties have been evaluated. Dynamic testing shows substantial damping (tan ?) measurable in each case. Nitinol film samples were tested in the Differential Scanning Calorimetry (DSC) to determine phase transformation temperatures. The twin boundary mechanism by which energy absorption occurs is present at all points below the Austenite start temperature (approximately 69°C in our film) and therefore allows damping at cold temperatures where traditional materials fail. Thin film in the NiTi/Si laminate was found to produce substantially higher damping (tan ? = 0.28) due to the change in loading condition. The NiTi/Si laminate sample was tested in bending allowing the twin boundaries to be reset by cyclic tensile and compressive loads. The thin film Terfenol-D in the Nitinol/Terfenol-D/Nickel laminate was shown to produce large damping (tan ? = 0.2). In addition to fabricating and testing, an analytical model of a heterogeneous layered thin film damping material was developed and compared to experimental work.

Kerrigan, Catherine A.; Ho, Ken K.; Mohanchandra, K. P.; Carman, Gregory P.

2007-04-01

200

High temperature superconducting thin film structure and method of making  

Microsoft Academic Search

This patent describes a high temperature superconducting thin film structure. It comprises: a substrate and a high {Tc} superconducting thin film spaced from the substrate, a diffusion barrier layer in the space between the substrate and the high {Tc} superconducting thin film wherein the diffusion barrier layer is lattice matched both to the substrate and to the superconducting film and

J. R. Shappirio; T. R. Aucion; J. J. Finnegan

1990-01-01

201

NANO-INDENTATION OF COPPER THIN FILMS ON SILICON SUBSTRATES  

E-print Network

NANO-INDENTATION OF COPPER THIN FILMS ON SILICON SUBSTRATES S. Suresh1 , T.-G. Nieh2 and B.W. Choi2: Mechanical properties; Nano-indentation; Thin films; Copper; Dislocations Introduction Indentation methods films on substrates (e.g., [2,3]) using instrumented indentation. Nano-indentation studies of thin films

Suresh, Subra

202

Evidence for spin mixing in holmium thin film and crystal samples  

NASA Astrophysics Data System (ADS)

In a number of recent experiments, holmium has been shown to promote spin-triplet pairing when in proximity to a spin-singlet superconductor. The condition for the support of spin-triplet pairing is that the ferromagnet should have an inhomogeneous magnetic state at the interface with the superconductor. Here we use Andreev reflection spectroscopy to study the properties of single ferromagnet/superconductor interfaces formed of holmium and niobium, as a function of the contact resistance of the junction between them. We find that both single-crystal and c-axis-oriented thin-film holmium show unusual behavior for low junction contact resistance, characteristic of spin-mixing-type properties, which are thought necessary to underpin spin-triplet formation. We also explore whether this signature is observed when the junction is formed of Ni0.19Pd0.81 and niobium.

Usman, I. T. M.; Yates, K. A.; Moore, J. D.; Morrison, K.; Pecharsky, V. K.; Gschneidner, K. A.; Verhagen, T.; Aarts, J.; Zverev, V. I.; Robinson, J. W. A.; Witt, J. D. S.; Blamire, M. G.; Cohen, L. F.

2011-04-01

203

Thermal conductivities of thin, sputtered optical films.  

PubMed

The normal component of thin-film thermal conductivity has been measured for the first time, to the best of our knowledge, for several advanced sputtered optical materials. Included are data for single layers of boron nitride, silicon aluminum nitride, silicon aluminum oxynitride, silicon carbide, and for dielectricenhanced metal reflectors of the form Al(SiO(2)/Si(3)N(4))(n) and Al(Al(2)O(3)/AlN)(n). Sputtered films of more conventional materials such as SiO(2), Al(2)O(3), Ta(2)O(5), Ti, and Si have also been measured. The data show that thin-film thermal conductivities are typically 10 to 100 times lower than conductivities for the same materials in bulk form. Structural disorder in the amorphous or fine-grained films appears to account for most of the conductivity difference. Conclusive evidence for a film-substrate interface contribution is presented. PMID:20802666

Henager, C H; Pawlewicz, W T

1993-01-01

204

Mesoscopically structured nanocrystalline metal oxide thin films.  

PubMed

This review describes the main successful strategies that are used to grow mesostructured nanocrystalline metal oxide and SiO2 films via deposition of sol-gel derived solutions. In addition to the typical physicochemical forces to be considered during crystallization, mesoporous thin films are also affected by the substrate-film relationship and the mesostructure. The substrate can influence the crystallization temperature and the obtained crystallographic orientation due to the interfacial energies and the lattice mismatch. The mesostructure can influence the crystallite orientation, and affects nucleation and growth behavior due to the wall thickness and pore curvature. Three main methods are presented and discussed: templated mesoporosity followed by thermally induced crystallization, mesostructuration of already crystallized metal oxide nanobuilding units and substrate-directed crystallization with an emphasis on very recent results concerning epitaxially grown piezoelectric structured ?-quartz films via crystallization of amorphous structured SiO2 thin films. PMID:25224841

Carretero-Genevrier, Adrian; Drisko, Glenna L; Grosso, David; Boissiere, Cédric; Sanchez, Clement

2014-11-01

205

Mirrorlike pulsed laser deposited tungsten thin film  

NASA Astrophysics Data System (ADS)

Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10-5 Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ˜782 nm.

Mostako, A. T. T.; Rao, C. V. S.; Khare, Alika

2011-01-01

206

Thin film dielectric composite materials  

DOEpatents

A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

Jia, Quanxi (Los Alamos, NM); Gibbons, Brady J. (Los Alamos, NM); Findikoglu, Alp T. (Los Alamos, NM); Park, Bae Ho (Los Alamos, NM)

2002-01-01

207

All thin film magnetoelectric magnetic field sensors.  

NASA Astrophysics Data System (ADS)

We have fabricated prototype ac magnetic field sensors operating at room temperature based on all thin film ME devices showing strong magnetoelectric (ME) coupling. The ME layers consist of a sol-gel derived Pb(Zr0.52Ti0.48)TiO3 (PZT) film and a dc magnetron sputter deposited magnetostrictive Fe70Ga30 (FeGa) film. The bilayer structures are prepared on micromachined Si wafers, and the laser cutting technique is used to release and isolate the cantilevers for optimization of the sensor performance. The PZT layer and the FeGa layer couple via the piezoelectric d31 mode and the corresponding ME coupling coefficient is as high as 2 V/(Oe cm) for a lateral dimension of 1 mm^2 device at the mechanical resonant frequency of 333 Hz of a Si cantilever. The soft magnetic FeGa film requires dc bias magnetic field of around 90 Oe to operate the thin film ME device. The coupling between the PZT and the FeGa films is remarkably improved by depositing a 40 nm thick Pt intermediate layer. The clamping effect on the ME coupling is dramatically reduced by back-etching the Si cantilever down to 35 ?m thick. The present work indicates presence of robust ME coupling in microfabricated multilayer thin film ME devices.

Zhao, Peng

2009-03-01

208

Method for synthesizing thin film electrodes  

DOEpatents

A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

Boyle, Timothy J. (Albuquerque, NM)

2007-03-13

209

Mesoscale morphologies in polymer thin films.  

SciTech Connect

In the midst of an exciting era of polymer nanoscience, where the development of materials and understanding of properties at the nanoscale remain a major R&D endeavor, there are several exciting phenomena that have been reported at the mesoscale (approximately an order of magnitude larger than the nanoscale). In this review article, we focus on mesoscale morphologies in polymer thin films from the viewpoint of origination of structure formation, structure development and the interaction forces that govern these morphologies. Mesoscale morphologies, including dendrites, holes, spherulites, fractals and honeycomb structures have been observed in thin films of homopolymer, copolymer, blends and composites. Following a largely phenomenological level of description, we review the kinetic and thermodynamic aspects of mesostructure formation outlining some of the key mechanisms at play. We also discuss various strategies to direct, limit, or inhibit the appearance of mesostructures in polymer thin films as well as an outlook toward potential areas of growth in this field of research.

Ramanathan, M.; Darling, S. B. (Center for Nanoscale Materials)

2011-06-01

210

Thin film ferroelectric electro-optic memory  

NASA Technical Reports Server (NTRS)

An electrically programmable, optically readable data or memory cell is configured from a thin film of ferroelectric material, such as PZT, sandwiched between a transparent top electrode and a bottom electrode. The output photoresponse, which may be a photocurrent or photo-emf, is a function of the product of the remanent polarization from a previously applied polarization voltage and the incident light intensity. The cell is useful for analog and digital data storage as well as opto-electric computing. The optical read operation is non-destructive of the remanent polarization. The cell provides a method for computing the product of stored data and incident optical data by applying an electrical signal to store data by polarizing the thin film ferroelectric material, and then applying an intensity modulated optical signal incident onto the thin film material to generate a photoresponse therein related to the product of the electrical and optical signals.

Thakoor, Sarita (Inventor); Thakoor, Anilkumar P. (Inventor)

1993-01-01

211

Thin Film Transistors On Plastic Substrates  

DOEpatents

A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The silicon based thin film transistor produced by the process includes a low temperature substrate incapable of withstanding sustained processing temperatures greater than about 250.degree. C., an insulating layer on the substrate, a layer of silicon on the insulating layer having sections of doped silicon, undoped silicon, and poly-silicon, a gate dielectric layer on the layer of silicon, a layer of gate metal on the dielectric layer, a layer of oxide on sections of the layer of silicon and the layer of gate metal, and metal contacts on sections of the layer of silicon and layer of gate metal defining source, gate, and drain contacts, and interconnects.

Carey, Paul G. (Mountain View, CA); Smith, Patrick M. (San Ramon, CA); Sigmon, Thomas W. (Portola Valley, CA); Aceves, Randy C. (Livermore, CA)

2004-01-20

212

Thin films of coordination polymer magnets.  

PubMed

Many applications of molecule based magnets, whether they are in information storage, displays, or as components in electronic or spintronic devices, will require putting the active materials on a surface or interfacing them with other components. Although there are many examples of molecule-based magnets, the families of tetracyanoethylene (TCNE) based magnets and Prussian-blue analogs possess materials properties that are close to those required for practical applications, and are the most advanced with respect to studies as thin films. This critical review focuses on fabrication and characterization of thin films of TCNE and Prussian-blue analog coordination polymer magnets. Emphasis is on current developments in thin film heterostructures and potential spintronics applications (135 references). PMID:21465059

Talham, Daniel R; Meisel, Mark W

2011-06-01

213

Thin film oxygen partial pressure sensor  

NASA Technical Reports Server (NTRS)

The development is described of a laboratory model oxygen partial pressure sensor using a sputtered zinc oxide thin film. The film is operated at about 400 C through the use of a miniature silicon bar. Because of the unique resistance versus temperature relation of the silicon bar, control of the operational temperature is achieved by controlling the resistance. A circuit for accomplishing this is described. The response of sputtered zinc oxide films of various thicknesses to oxygen, nitrogen, argon, carbon dioxide, and water vapor caused a change in the film resistance. Over a large range, film conductance varied approximately as the square root of the oxygen partial pressure. The presence of water vapor in the gas stream caused a shift in the film conductance at a given oxygen partial pressure. A theoretical model is presented to explain the characteristic features of the zinc oxide response to oxygen.

Wortman, J. J.; Harrison, J. W.; Honbarrier, H. L.; Yen, J.

1972-01-01

214

Fast, precise, tomographic measurements of thin films  

SciTech Connect

The authors describe a nondestructive measurement method that enables them to obtain the cross-sectional thickness profile of thin-film layers fast with a single operation of measurement. The method is based on spectrally resolved white-light interferometry, being capable of reconstructing the tomographic height map of thin films with depth resolutions in the nanometer range. In terms of the measuring speed and resolution, the proposed method is well suited for the in-line high-speed inspection of microelectronics devices produced in large quantities particularly in the semiconductors and flat panel displays industries.

Ghim, Young-Sik; Kim, Seung-Woo [Billionth Uncertainty Precision Engineering Group, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Science Town, Daejeon 305-701(Korea, Republic of)

2007-08-27

215

Micro-sensor thin-film anemometer  

NASA Technical Reports Server (NTRS)

A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

Sheplak, Mark (Inventor); McGinley, Catherine B. (Inventor); Spina, Eric F. (Inventor); Stephens, Ralph M. (Inventor); Hopson, Jr., Purnell (Inventor); Cruz, Vincent B. (Inventor)

1996-01-01

216

Emittance Theory for Thin Film Selective Emitter  

NASA Technical Reports Server (NTRS)

Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

Chubb, Donald L.; Lowe, Roland A.; Good, Brian S.

1994-01-01

217

Feasibility Study of Thin Film Thermocouple Piles  

NASA Technical Reports Server (NTRS)

Historically, thermopile detectors, generators, and refrigerators based on bulk materials have been used to measure temperature, generate power for spacecraft, and cool sensors for scientific investigations. New potential uses of small, low-power, thin film thermopiles are in the area of microelectromechanical systems since power requirements decrease as electrical and mechanical machines shrink in size. In this research activity, thin film thermopile devices are fabricated utilizing radio frequency sputter coating and photoresist lift-off techniques. Electrical characterizations are performed on two designs in order to investigate the feasibility of generating small amounts of power, utilizing any available waste heat as the energy source.

Sisk, R. C.

2001-01-01

218

Heterogeneous Thin Films of Martensitic Materials  

Microsoft Academic Search

:  We study the effective behavior of heterogeneous thin films with three competing length scales: the film thickness and the\\u000a length scales of heterogeneity and material microstructure. We start with three-dimensional nonhomogeneous nonlinear elasticity\\u000a enhanced with an interfacial energy of the van der Waals type, and derive the effective energy density as all length scales\\u000a tend to zero with given limiting

Y. C. Shu

2000-01-01

219

Thin film effects in ultrasonic wafer thermometry  

Microsoft Academic Search

We use an ultrasonic technique where the temperature dependence of lowest order anti-symmetric Lamb wave velocity in the silicon wafer is utilized for in-situ temperature measurement in the 20-1000°C range. In almost all wafer processing steps, one or more layers of thin films are present on the wafers. The effects of these films on temperature sensitivity is investigated. A theoretical

F. L. Degertekin; J. Pei; B. V. Honein; B. T. Khuri-Yakub; K. C. Saraswat

1994-01-01

220

Annealed CVD molybdenum thin film surface  

DOEpatents

Molybdenum thin films deposited by pyrolytic decomposition of Mo(CO).sub.6 attain, after anneal in a reducing atmosphere at temperatures greater than 700.degree. C., infrared reflectance values greater than reflectance of supersmooth bulk molybdenum. Black molybdenum films deposited under oxidizing conditions and annealed, when covered with an anti-reflecting coating, approach the ideal solar collector characteristic of visible light absorber and infrared energy reflector.

Carver, Gary E. (Tucson, AZ); Seraphin, Bernhard O. (Tucson, AZ)

1984-01-01

221

Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films  

SciTech Connect

OAK B204 Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films. The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and hTi-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials.

Hellman, Frances

1998-10-03

222

Thin film micro carbon dioxide sensor using MEMS process  

Microsoft Academic Search

Pt\\/Na+ ion conductive ceramic thin film\\/Pt\\/carbonate (Na2CO3:BaCO3=1:1.7mol) system CO2 micro gas sensor was fabricated and the sensing properties were investigated. The Na+ ion conductive thin film was prepared by RF magnetron sputtering method. The thin film micro carbon dioxide sensor was prepared by using silicon process combined with MEMS technology.A NASICON thin film (2000–2500Å) as main layer of the device

Yeung-Il Bang; Kap-Duk Song; Byung-Su Joo; Jeung-Soo Huh; Soon-Don Choi; Duk-Dong Lee

2004-01-01

223

Workshop on thin film thermal conductivity measurements  

NASA Astrophysics Data System (ADS)

On a subject of considerable import to the laser-induced damage community, a two day workshop on the topic, Thin Film Thermal Conductivity Measurement was held as part of the 13th Symposium on Thermophysical Properties at the University of Colorado in Boulder CO, June 25 and 26, 1997. The Workshop consisted of 4 sessions of 17 oral presentations and two discussion sessions. Two related subjects of interest were covered; 1) methods and problems associated with measuring thermal conductivity ((kappa) ) of thin films, and 2) measuring and (kappa) of chemical vapor deposited (CVD) diamond. On the subject of thin film (kappa) measurement, several recently developed imaginative techniques were reviewed. However, several authors disagreed on how much (kappa) in a film differs from (kappa) in a bulk material of the same nominal composition. A subject of controversy was the definition of an interface. In the first discussion session, several questions were addressed, a principal one being, how do we know that the values of (kappa) we obtain are correct and is there a role for standards in thin film (kappa) measurement. The second discussion session was devoted to a round-robin interlaboratory comparison of (kappa) measurements on a set of CVD diamond specimens and several other specimens of lower thermal conductivity. Large interlaboratory differences obtained in an earlier round robin had been attributed to specimen inhomogeneity. Unfortunately, large differences were also observed in the second round robin even though the specimens were more homogenous. There was good consistency among the DC measurements, however, the AC measurements showed much greater variability. There was positive feedback from most of the attenders regarding the Workshop with nearly all respondents recommending another Workshop in three or fewer years. There was general recognition that thin film thermal conductivity measurements are important for predicting the resistance of optical coating materials to laser damage.

Feldman, Albert; Balzaretti, Naira M.; Guenther, Arthur H.

1998-04-01

224

Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films  

NASA Technical Reports Server (NTRS)

Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation forces, e.g. microgravity - magnetic damping devices.

Schoenhuber, P.; Moon, F. C.

1995-01-01

225

(119) Bi2223 thin films grown by MOCVD on (100) NdGaO3 and (110) SrTiO3  

Microsoft Academic Search

In high temperature superconductors (HTS) the coherence length along non-c axis directions is longer. This feature can be useful wh en designing electronics devices based on HTS. Therefore growth and characterization of non-c axis oriented thin HTS films is of great interest. In this paper we present a short review of our data regarding (119) Bi-2223 thin films grown by

Kazuhiro Endo; P. Badica

2002-01-01

226

Growth induced magnetic anisotropy in crystalline and amorphous thin films  

SciTech Connect

The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and Ni-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials. A brief summary of work done in each area is given.

Hellman, F.

1998-07-20

227

Effective optical properties of absorbing nanoporous and nanocomposite thin films  

E-print Network

Effective optical properties of absorbing nanoporous and nanocomposite thin films Anna Garahan In recent years, synthesis and characterization of nano- composite thin films in general and nanoporous the through-plane effective index of refraction and absorption index of nanocomposite thin films. First

Pilon, Laurent

228

Thermal analysis of thin-film micromachining with lasers  

Microsoft Academic Search

Laser micromachining of thin metallic films is promising to become an important processing step in the fabrications of electronic circuits. Important applications range from pattern generation of conductive paths to trimming of thinfilm resistors. Since the thin films possess vaporization temperatures which generally are much higher than the melting temperature of the underlying dielectric substrate, short — duration

U. C. Paek; A. Kestenbaum

1973-01-01

229

Block copolymer thin films with long-range lateral order  

NASA Astrophysics Data System (ADS)

We investigated thin block copolymer films on silicon wafers as well as faceted surfaces of sapphire. Thin films were prepared by spin-coating block copolymer solutions on the corresponding substrates. Subsequent annealing in organic solvent vapors served as a means to induce lateral long-range order in the thin films. The resulting block copolymer structures were analyzed by AFM and GISAXS.

Gunkel, Ilja; Xu, Ting; Hexemer, Alexander; Russell, Thomas

2012-02-01

230

Crystallographic studies on hexaphenyl thin films — a review  

Microsoft Academic Search

Thin films of hexaphenyl show interesting crystallographic features, which are of great importance for technological applications. The textures and the sizes of the crystallites have large influence on the electronic and optical properties of the thin films. Hexaphenyl thin films are prepared by physical vapour deposition on various types of substrates: isotropic and mechanical pre-treated substrates or single crystalline surfaces.

Roland Resel

2003-01-01

231

Simulation of dislocations and strength in thin films: A review  

Microsoft Academic Search

Crystalline thin films have mechanical properties that cannot be predicted based on bulk scaling laws. Owing to their importance in technology, a great deal of effort has gone into modeling and simulation of the behaviors of dislocations in thin films. In this review, the successes and failures of modeling dislocations in thin films via analytical techniques, 2D dislocation dynamics simulations,

Ray S. Fertig; Shefford P. Baker

2009-01-01

232

RF sputtered piezoelectric zinc oxide thin film for transducer applications  

E-print Network

on the piezoelectric and crystalline qualities of the ZnO thin films. Experimental results showed that the multilayer, and bulk acoustic wave (BAW) devices [1]. A strategic advantage of deposited ZnO thin film on the quality of the piezoelectric ZnO thin films. Substantial research efforts have been devoted to the studies

Tang, William C

233

Photoluminescence studies on RF plasma-polymerized thin films  

Microsoft Academic Search

Conjugated polymers in the form of thin films play an important role in the field of materials science due to their interesting properties. Polymer thin films find extensive applications in the fabrication of devices, such as light emitting devices, rechargeable batteries, super capacitors, and are used as intermetallic dielectrics and EMI shieldings. Polymer thin films prepared by plasma-polymerization are highly

S. Saravanan; C. Joseph Mathai; M. R. Anantharaman; S. Venkatachalam; D. K. Avasthi; F. Singh

2005-01-01

234

Electronic transport properties of topological insulator films and low dimensional superconductors  

NASA Astrophysics Data System (ADS)

In this review, we present a summary of some recent experiments on topological insulators (TIs) and superconducting nanowires and films. Electron-electron interaction (EEI), weak anti-localization (WAL) and anisotropic magneto-resistance (AMR) effect found in topological insulator films by transport measurements are reported. Then, transport properties of superconducting films, bridges and nanowires and proximity effect in non-superconducting nanowires are described. Finally, the interplay between topological insulators and superconductors (SCs) is also discussed.

Xing, Ying; Sun, Yi; Singh, Meenakshi; Zhao, Yan-Fei; Chan, Moses H. W.; Wang, Jian

2013-10-01

235

Nanostructured Thin Film Electrolyte for Thin Film Solid Oxide Fuel Cells  

E-print Network

under reducing conditions. The results suggest that the YSZ thin film serves as a blocking layer for preventing electrical current leakage in the GDC layer and also provides chemical, mechanical, and structural integrity in the cell, which leads...

Cho, Sungmee

2012-10-19

236

UV absorption control of thin film growth  

DOEpatents

A system for monitoring and controlling the rate of growth of thin films in an atmosphere of reactant gases measures the UV absorbance of the atmosphere and calculates the partial pressure of the gases. The flow of reactant gases is controlled in response to the partial pressure.

Biefeld, Robert M. (Albuquerque, NM); Hebner, Gregory A. (Albuquerque, NM); Killeen, Kevin P. (Albuquerque, NM); Zuhoski, Steven P. (Hopewell Junction, NY)

1991-01-01

237

PLD growth of thin film Zinc Phosphide  

NASA Astrophysics Data System (ADS)

The development of efficient, low cost solar cells to meet society's growing energy needs has triggered tremendous interest in developing photovoltaics formed from earth abundant materials. Zinc phosphide (Zn3P2) is a promising earth abundant absorber layer for photovoltaic energy conversion with a nearly ideal band gap (1.5eV) and a large absorption coefficient of 10^4/cm. In this work we examine the growth parameters, electrical and optical properties of thin film zinc phosphide produced using pulsed laser deposition (PLD) from a zinc phosphide target at laser fluencies ranging from 1-3 J/cm2. For the laser fluences explored, highly resistive amorphous zinc phosphide thin films were produced with a band gap of approximately 1.7 eV. The thin films could be transformed from amorphous to polycrystalline zinc phosphide by annealing at 400C for 15mins in a N2 atmosphere. High resolution X-ray photoelectron spectroscopy (XPS) is used to examine the binding energies of Zn 2p3/2 and Phosphorous 2p3/2 signals and are in the range of 1021.6 eV and 127.5 eV. Energy Dispersive X-ray Spectroscopy (EDAX) revealed that the Zn3P2 thin films are nearly stoichiometric in composition. Hall mobility in these materials and Zn3P2/ZnS hetrojunction solar cell performance will be discussed.

Vaddi, Rajesh; Vasekar, Parag; Westgate, Charles; White, Bruce

2013-03-01

238

Analysis of hydrogen isotopes in thin films  

Microsoft Academic Search

Mass spectrometer modifications made for high resolution analysis of hydrogen isotopes outgassed from occluder thin films are described. The electronic modifications made to the source, magnet power supply, and scanning circuits provided increased precision in the mass range 2 to 6. Routine analyses were made at a resolution of 1300 with a Faraday cup detector. Extensive modification of the inlet

T. K. Mehrhoff; J. O. Humphries

1976-01-01

239

Anemometer with hot platinum thin film  

Microsoft Academic Search

The techniques of micromachining silicon are used for the manufacture of an anemometer with low electric consumption and great sensitivity. To reduce the energy consumption, a suspended membrane of silicon rich silicon nitride SiNx makes it possible to carry out the heat insulation between the heater and the substrate. Platinum (Pt) thin film (3000Å) with titanium (300Å) adhesion layer on

F Mailly; A Giani; R Bonnot; P Temple-Boyer; F Pascal-Delannoy; A Foucaran; A Boyer

2001-01-01

240

Thin Solid Films 517 (2009) 34663471  

E-print Network

Thin Solid Films 517 (2009) 3466­3471 DOI: http://dx.doi.org/10.1016/j.tsf.2009.01.079 Gas elements is described in detail. According to these simulations taking into account optical emission-temperature route (b1000 °C), was the synthesis way to filamentous carbon used in the sixties, and seems promising

Paris-Sud XI, Université de

241

Diamagnetism of Thin Films of Bismuth  

Microsoft Academic Search

AT Prof. W. Gerlach's suggestion I have recently investigated the behaviour of the magnetic susceptibility of bismuth when measured in the form of thin films. A modified form of the Faraday method was employed, the measuring system consisting of a flat cross with four equal arms about 15 mm. long and 5 mm. wide, the arms being set at about

1932-01-01

242

Microscale heat conduction in dielectric thin films  

Microsoft Academic Search

Starting from fundamental principles, it is shown that heat conduction by phonons can be analyzed in radiative transfer. A general theory of heat conduction is developed, showing that the Fourier law is a limiting case for steady-state macroscale heat transport. Two cases of heat transport across and along a thin film are considered. For the transient case, the theory shows

A. Majumdar

1993-01-01

243

Thin film hydrous metal oxide catalysts  

DOEpatents

Thin film (<100 nm) hydrous metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM)

1995-01-01

244

Magnetooptical investigations on thin ferromagnetic films  

Microsoft Academic Search

Various applications of the Faraday and Kerr effects for the investigation of domain structures and reversal mechanisms in thin ferromagnetic films are reviewed. Different optical arrangements for the observation of domains are described and compared. Using magnetooptic microscopy domains and wall structures can be observed with a resolution of 1 ?m. Magnetization structures give rise to diffraction phenomena, which are

M. Lambeck

1968-01-01

245

Thin-Film Solid Oxide Fuel Cells  

NASA Technical Reports Server (NTRS)

The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

2009-01-01

246

Tunable thin film filters: review and perspectives  

Microsoft Academic Search

The development of tunable filters is a key point for the ability of optical telecommunication networks to comply with the continuous evolution of the service providers needs. Among the numerous technologies which can be used to achieve narrow bandpass filtering devices, we concentrate our analysis on Thin-Film Interference Coatings and compare the principles, performances and use constraints of the various

Michel Lequime

2004-01-01

247

Workshop on thin film thermal conductivity measurements  

Microsoft Academic Search

On a subject of considerable import to the laser-induced damage community, a two day workshop on the topic, Thin Film Thermal Conductivity Measurement was held as part of the 13th Symposium on Thermophysical Properties at the University of Colorado in Boulder CO, June 25 and 26, 1997. The Workshop consisted of 4 sessions of 17 oral presentations and two discussion

Albert Feldman; Naira M. Balzaretti; Arthur H. Guenther

1998-01-01

248

Thin film thermocouples for high temperature measurement  

NASA Astrophysics Data System (ADS)

Thin film thermocouples have unique capabilities for measuring surface temperatures at high temperatures (above 800 K) under harsh conditions. Their low mass, approximately 2 x 10(-5) g/mm permits very rapid response and very little disturbance of heat transfer to the surface being measured. This has led to applications inside gas turbine engines and diesel engines measuring the surface temperature of first stage turbine blades and vanes and ceramic liners in diesel cylinders. The most successful high temperature (up to 1300 K) thin film thermocouples are sputter deposited from platinum and platinum-10 percent rhodium targets although results using base metal alloys, gold, and platinel will also be presented. The fabrication techniques used to form the thermocouples, approaches used to solve the high temperature insulation and adherence problems, current applications, and test results using the thin film thermocouples are reviewed. In addition a discussion will be presented on the current problems and future trends related to applications of thin film thermocouples at higher temperatures up to 1900 K.

Kreider, Kenneth G.

1989-05-01

249

Residual stress measurement in YBCO thin films.  

SciTech Connect

Residual stress in YBCO films on Ag and Hastelloy C substrates was determined by using 3-D optical interferometry and laser scanning to measure the change in curvature radius before and after film deposition. The residual stress was obtained by appropriate analysis of curvature measurements. Consistent with residual thermal stress calculations based on the thermal expansion coefficient mismatch between the substrates and YBCO film, the measured residual stress in the YBCO film on Hastelloy C substrate was tensile, while it was compressive on the Ag substrate. The stress values measured by the two techniques were generally in good agreement, suggesting that optical interferometry and laser scanning have promise for measuring residual stresses in thin films.

Cheon, J. H.; Singh, J. P.

2002-05-13

250

Thin film piezoelectric property considerations for surface acoustic wave and thin film bulk acoustic resonators  

Microsoft Academic Search

We report on the optimisation of thin film piezoelectric ZnO for production of resonant acoustic MEMS devices (SAW and FBAR\\/BAW). The ZnO was deposited by RF sputtering, and conditions were optimised to promote uniform polycrystalline orientation, high resistivity and smooth surface morphology. Both surface acoustic wave and thin film bulk acoustic resonators exhibited high Q values with low insertion loss

P. B Kirby; M. D. G Potter; C. P Williams; M. Y Lim

2003-01-01

251

Electromagnetic fluctuations near thin metallic films  

NASA Astrophysics Data System (ADS)

We compute the electromagnetic fluctuations due to evanescent-wave Johnson noise in the vicinity of a thin conducting film, such as a metallic gate or a two-dimensional electron gas. This noise can decohere a nearby qubit, and it is also responsible for heat transfer and Casimir forces. We have improved on previous calculations of decoherence rates by including the nonlocal dielectric response of the film, which is an important correction at short distances. Remarkably, the fluctuations responsible for decoherence of charge qubits from a thin film are greatly enhanced over those arising from a conducting half space. The decoherence times can be reduced by over an order of magnitude by decreasing the film thickness. This appears to be due to the leakage into the vacuum of modes that are well localized in the perpendicular direction. There is no corresponding effect for spin qubits (magnetic field fluctuations). We also show that a nonlocal dielectric function naturally removes the divergence in the Casimir force at vanishing separation between two metallic sheets or half spaces. In the separation regime where local and nonlocal treatments are noticeably distinct, the Casimir attraction between two thin sheets and two half spaces is practically indistinguishable for any physical film thickness.

Langsjoen, Luke S.; Poudel, Amrit; Vavilov, Maxim G.; Joynt, Robert

2014-03-01

252

Slip-controlled thin film dynamics  

E-print Network

In this study, we present a novel method to assess the slip length and the viscosity of thin films of highly viscous Newtonian liquids. We quantitatively analyse dewetting fronts of low molecular weight polystyrene melts on Octadecyl- (OTS) and Dodecyltrichlorosilane (DTS) polymer brushes. Using a thin film (lubrication) model derived in the limit of large slip lengths, we can extract slip length and viscosity. We study polymer films with thicknesses between 50 nm and 230 nm and various temperatures above the glass transition. We find slip lengths from 100 nm up to 1 micron on OTS and between 300 nm and 10 microns on DTS covered silicon wafers. The slip length decreases with temperature. The obtained values for the viscosity are consistent with independent measurements.

R. Fetzer; M. Rauscher; A. Münch; B. A. Wagner; K. Jacobs

2006-03-17

253

Thin film multiferroic nanocomposites by ion implantation.  

PubMed

Thin film multiferroic nanocomposites might enable a range of potentially disruptive integrated magnetoelectric devices for information storage, spintronics, microwave telecommunications, and magnetic sensing. With this aim, we have investigated ion implantation of magnetic species into ferroelectric single crystal targets as a radically novel approach to prepare film nanoparticulate magnetic-metal ferroelectric-oxide composites. These materials are an alternative to multiferroic oxide epitaxial columnar nanostructures that are under intensive research, but whose magnetoelectric response is far from expectations. Here, we unambiguously demonstrate the preparation of such a thin film multiferroic nanocomposite of Co and BaTiO3 by ion implantation of a high dose of the magnetic species, followed by rapid thermal processing under tailored conditions. Results thus constitute a proof of concept for the feasibility of obtaining the materials by this alternative approach. Ion implantation is a standard technique for the microelectronic industry in combination with well-established patterning procedures. PMID:24417708

Algueró, Miguel; Ricote, Jesús; Torres, María; Amorín, Harvey; Alberca, Aurora; Iglesias-Freire, Oscar; Nemes, Norbert; Holgado, Susana; Cervera, Manuel; Piqueras, Juan; Asenjo, Agustina; García-Hernández, Mar

2014-02-12

254

MISSE 5 Thin Films Space Exposure Experiment  

NASA Technical Reports Server (NTRS)

The Materials International Space Station Experiment (MISSE) is a set of space exposure experiments using the International Space Station (ISS) as the flight platform. MISSE 5 is a co-operative endeavor by NASA-LaRC, United Stated Naval Academy, Naval Center for Space Technology (NCST), NASA-GRC, NASA-MSFC, Boeing, AZ Technology, MURE, and Team Cooperative. The primary experiment is performance measurement and monitoring of high performance solar cells for U.S. Navy research and development. A secondary experiment is the telemetry of this data to ground stations. A third experiment is the measurement of low-Earth-orbit (LEO) low-Sun-exposure space effects on thin film materials. Thin films can provide extremely efficacious thermal control, designation, and propulsion functions in space to name a few applications. Solar ultraviolet radiation and atomic oxygen are major degradation mechanisms in LEO. This paper is an engineering report of the MISSE 5 thm films 13 months space exposure experiment.

Harvey, Gale A.; Kinard, William H.; Jones, James L.

2007-01-01

255

WO 3 sputtered thin films for NO x monitoring  

Microsoft Academic Search

We present in this paper preliminary results concerning the preparation of tungsten trioxide thin films by reactive sputtering, the characterization either of their structural properties by means of XRD measurements or of the film morphology with the AFM microscope and the electrical response of the film towards toxic and pollutant gases. WO3 thin films showed a good sensitivity towards low

G. Sberveglieri; L. Depero; S. Groppelli; P. Nelli

1995-01-01

256

Characterization of nanomechanical and piezoelectric properties of AlN thin film for thin film bulk acoustic wave resonators  

Microsoft Academic Search

In last few years, with the strong progress in thin film technologies for complex materials systems such as PZT, ZnO and AlN, thin film bulk acoustic wave resonator (FBAR) and filter concepts are gaining more and more importance for microwave frequency control applications. For resonators operating in the GHz range, piezoelectric thin film layer in the order of a few

Qingming Chen; Fang Li; Qing-Ming Wang

2006-01-01

257

Processing and Gas Barrier Behavior of Multilayer Thin Nanocomposite Films  

E-print Network

loadings, creating super gas barrier thin films on substrates normally exhibiting high gas permeability. Branched polyethylenimine (PEI) and poly (acrylic acid) (PAA) were deposited using LbL to create gas barrier films with varying pH combinations. Film...

Yang, You-Hao

2012-10-19

258

Transverse freezing of thin liquid films  

NASA Astrophysics Data System (ADS)

A pair of coupled non-linear partial differential equations is derived using lubrication theory that govern the morphology of a thin, liquid film of a pure and a binary metal alloy, bounded by the liquid's solid phase and a passive gas phase. The analysis is motivated by the directional freezing of metallic foams, and is a first attempt to model transverse freezing in thin films that form in foam networks, but also applies to thin film layers in general. Both the no-slip crystal-melt and the free melt-gas interfaces are deformable. The governing pair of non-linear differential equations for the most general case incorporate crystal-melt and melt-gas surface tension, latent heat, heat transfer, volume change, molecular interactions, thermocapillary and dilute phase concentration effects. Linear analysis of a uniform film reveals a variety of instabilities. A unique wavenumber is selected at the onset of instability in the case of an applied temperature gradient with vanishing crystal-melt surface tension. This system reproduces the isothermal result for a rigid solid-liquid interface in which a band of wavenumbers is unstable. A new long-wave instability has been identified, for the case with CM surface tension, that is due to the coupling of the interfaces. Numerical solutions of the fully non-linear system provide film evolution and rupture times, and show that, near the critical conditions, rupture can occur by the growth of standing or traveling waves. The numerics also reveals complex non-linear interactions between unstable modes. It is found that for most unstable initial conditions, the crystal-melt interface retreats by melting away from the tip region of the encroaching melt-gas interface due to a rise in heat flux as the film thins near the rupture point.

Beerman, Michael

259

AN EFFECTIVE PASSIVATION FILM STACK FOR THIN FILM BST CAPACITORS  

Microsoft Academic Search

Thin film voltage tunable ferroelectric capacitors on various substrates are promising for use in high power microwave and other RF systems. Benefits of ferroelectric capacitors include miniaturization and integration with other passive devices.Commercialization of ferroelectric components requires compliance with certain industry standards for reliability. For ferroelectric capacitors the requirement to pass the THB test requires a silicon nitride layer in

M. ZELNER; S. NAGY; A. CERVIN-LAWRY; M. CAPANU; T. BERNACKI; C. DIVITA

2008-01-01

260

Critical Dynamics in Thin Films  

Microsoft Academic Search

Critical dynamics in film geometry is analyzed within the field-theoretical approach. In particular we consider the case of purely relaxational dynamics (Model A) and Dirichlet boundary conditions, corresponding to the so-called ordinary surface universality class on both confining boundaries. The general scaling properties for the linear response and correlation functions and for dynamic Casimir forces are discussed. Within the Gaussian

A. Gambassi; S. Dietrich

2006-01-01

261

Magnetic Structure of Engineered Multiferroic Thin Films  

NASA Astrophysics Data System (ADS)

The intriguing properties of multiferroics, i.e., materials exhibiting the coexistence of magnetism and ferroelectricity, have stimulated intense research interest in recent years. From the viewpoint of practical applications, one needs to exploit the thin film architectures of multiferroic materials. However, fewer studies have addressed the magnetic structures of multiferroic thin films. I will present recent experimental works on two multiferroic films, BiFeO3 and EuTiO3, physical properties of which can be engineered via the epitaxial growth on appropriate substrates. Neutron diffraction studies on BiFeO3 films deposited on vicinal SrTiO3 substrates show that the magnetic structure of these films is closely correlated with the ferroelectric states that depend on the chosen substrate miscut [1]. Epitaxial EuTiO3 grown on DyScO3 susbtrate, which is a paraelectric antiferromagnet in its bulk form, is strain-tuned into multiferroics, displaying both ferroelectric and ferromagnetic characters [2]. The relationship between the strong magnetic anisotropy and the film microstructure will be discussed. [4pt] [1] X. Ke, P. P. Zhang, S. Baek, J. Zarestky, W. Tian, and C. B. Eom, Phys. Rev. B 82, 134448 (2010). [0pt] [2] J. H. Lee, L. Fang, E. Vlahos, X. Ke, Y.W. Jung et al., Nature 466, 954 (2010).

Ke, Xianglin

2011-03-01

262

Electrodeposition of CdTe thin films  

SciTech Connect

Cadmium telluride thin films were fabricated on Ti and Nesatron substrates by electrodeposition and characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analyses (EDAX), optical transmission measurements, and photoelectrochemical (PEC) studies. The deposition-bath preparation procedure was slightly modified from the literature method to permit initial speciation of TeO/sub 2/ and thereby increase the loading level of Te in the film. New data are presented on the electrochemistry of the deposition process and on the cyclic voltammetric behavior of TeO/sub 2/ containing electrolytes in the pH range from about 0.7 to 11.0. The films after suitable annealing in an Ar atmosphere show x-ray diffraction behavior consistent with a hexagonal structure. Data from EDAX show that the Cd/Te ratio in the film is sensitive to the annealing process. Concomitantly, the conductivity also changes from p-type to n-type, as shown by PEC measurements on the films containing a protective ..cap alpha..-PbO/sub 2/ coating in contact with alkaline polysulfide electrolytes. Finally, some preliminary data are presented on PEC cells based on these CdTe thin films in a nonaqueous electrolyte system comprising the ferrocene/ferricenium ion redox couple.

Bhattachurya, R.N.; Rajeshwar, K.

1984-09-01

263

Magnon dispersion in thin magnetic films  

NASA Astrophysics Data System (ADS)

Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu3Au(1?0?0) and present new studies on Co and Ni thin films on Cu(1?0?0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1?0?0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations.

Balashov, T.; Buczek, P.; Sandratskii, L.; Ernst, A.; Wulfhekel, W.

2014-10-01

264

Application-related properties of giant magnetostrictive thin films  

NASA Astrophysics Data System (ADS)

In an effort to facilitate the utilization of giant magnetostrictive thin films in microdevices, application-related properties of these thin films, which include induced anisotropy, residual stress and corrosion properties, are investigated. A large induced anisotropy with an energy of 6×10 4 J/m 3 is formed in field-sputtered amorphous Sm-Fe-B thin films, resulting in a large magnetostriction anisotropy. Two components of residual stress, intrinsic compressive stress and tensile stress due to the difference of the thermal expansion coefficients between the substrate and thin film, are identified. The variation of residual stress with fabrication parameter and annealing temperature, and its influence on mechanical bending and magnetic properties are examined. Better corrosion properties are observed in Sm-Fe thin films than in Tb-Fe. Corrosion properties of Tb-Fe thin films, however, are much improved with the introduction of nitrogen to the thin films without deteriorating magnetostrictive properties.

Lim, S. H.; Kim, H. J.; Na, S. M.; Suh, S. J.

2002-02-01

265

Ferroelectric Thin Films for Electronic Applications  

NASA Astrophysics Data System (ADS)

This study yokes together the feasibility of a family of PbO-based perovskite-structured ferroelectric thin films as functional elements in nonvolatile random access memories (NVRAMs), in high capacity dynamic RAMs, and in a new class of flexure wave piezoelectric ultrasonic micromotors. The dielectric and ferroelectric properties of lead zirconate titanate (PZT) thin films were dependent on thickness; at saturation, the films were characterized by a relative permittivity of 1300, remanent polarization of 36 muC/cm^2 and breakdown strength of over 1 MV/cm. The temperature dependence of permittivity revealed an anomalous behavior with the film annealing temperature. Based on the ferroelectric properties in the bulk, thin films in the lead zirconate -lead zinc niobate (PZ-PZN) solid solution system at 8-12% PZN, examined as alternate compositions for ferroelectric memories, feature switched charges of 4-14 mu C/cm^2, with coercive and saturation voltages less than the semiconductor operating voltage of 5 V. Rapid thermally annealed lead magnesium niobate titanate films were privy to weak signal dielectric permittivity of 2900, remanent polarization of 11 muC/cm^2, and a storage density of 210 fC/mum^2 at 5 V; the films merit consideration for potential applications in ultra large scale integrated circuits as also ferroelectric nonvolatile RAMs. The high breakdown strength and relative permittivity of the PZT films entail maximum stored energy density 10^3 times larger than a silicon electrostatic motor. The longitudinal piezoelectric strain coefficient d_{33 } was measured to be 220 pC/N at a dc bias of 75 kV/cm. The transverse piezoelectric strain coefficient d_{31} bore a nonlinear relationship with the electric field; at 200 kV/cm, d _{31} was -88 pC/N. The development of the piezoelectric ultrasonic micromotors from the PZT thin films, and the architecture of the stator structures are described. Nonoptimized prototype micromotors show rotational velocities of 100-300 rpm at drives of 3-5 V.

Udayakumar, K. R.

266

Polycrystalline thin film materials and devices  

SciTech Connect

Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. (Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion)

1992-10-01

267

Thin film phase transition materials development program  

NASA Astrophysics Data System (ADS)

A number of application concepts have emerged based on the idea that a phase transition thin film such as vanadium dioxide provides a high resolution, two-dimensional format for switching, recording, and processing optical signals. These applications range from high density optical disk recording systems and optical data processing to laser protection devices, infrared FLIRS and seekers, laser radar systems and IR scene simulators. All application candidates have a potential for providing either a totally new capability, an improved performance, a lower cost, or combinations of the three. Probably of greatest significance is the emergence of agile sensor concepts arising out of some of the film's special properties. These are represented by the above FLIRs, seekers and laser radar systems. A three year research program has been completed to advance the state-of-the-art in the preparation and characterization of selected thin film phase transition materials. The objectives of the program were: (1) to expand the data base and improve operational characteristics of Vought prepared vanadium dioxide thin films, (2) to evolve process chemistry and subsequently characterize several new program materials, including rare-earth chalcogenides, organic semiconductor charge complexes, alloys of transition metal oxides, and metal-insulator cermets, and (3) to spin-off new applications and concepts.

Case, W. E.

1985-04-01

268

Borides in thin film technology  

SciTech Connect

The borides of transition and rare-earth metals are considered for application as wear- and corrosion-resistant, decorative or thermionic coatings. After a review of physical vapor deposition (PVD) techniques used for the deposition of these coatings, a survey of investigations to apply these coatings is given. As a result of the strong directionality of covalent boron-boron bonds, boride coatings show an increasing tendency to amorphous film growth with increasing B/Me atomic ratio and, for rare-earth hexaborides, with decreasing metallic radius of the rare-earth metal. Mechanical and optical properties are strongly influenced by the crystallographic structure of the boride phase. Because of their high hardness combined with good adhesion, crystalline films based on the diborides of transition metals seem to be promising candidates for wear resistant coatings on cutting tools. Alloying of these films with nitrogen by reactive PVD processes results in the formation of extremely fine-grained multiphase hard coatings with excellent tribological and corrosion behavior, thus offering new applications in the coating of engineering components. Because of their distinct colorations, some of the hexaborides of rare-earth elements may be used as decorative coatings on consumer products like wristwatch casings or eyeglass frames. Another promising field is the development of thermionic coatings based on rare-earth hexaborides, which may offer the possibility of the production of inexpensive and simple high emission filaments.

Mitterer, C. [Institut fuer Metallkunde und Werkstoffpruefung, Leoben (Austria)] [Institut fuer Metallkunde und Werkstoffpruefung, Leoben (Austria)

1997-10-01

269

Borides in Thin Film Technology  

NASA Astrophysics Data System (ADS)

The borides of transition and rare-earth metals are considered for application as wear- and corrosion-resistant, decorative or thermionic coatings. After a review of physical vapor deposition (PVD) techniques used for the deposition of these coatings, a survey of investigations to apply these coatings is given. As a result of the strong directionality of covalent boron-boron bonds, boride coatings show an increasing tendency to amorphous film growth with increasing B/ Meatomic ratio and, for rare-earth hexaborides, with decreasing metallic radius of the rare-earth metal. Mechanical and optical properties are strongly influenced by the crystallographic structure of the boride phase. Because of their high hardness combined with good adhesion, crystalline films based on the diborides of transition metals seem to be promising candidates for wear resistant coatings on cutting tools. Alloying of these films with nitrogen by reactive PVD processes results in the formation of extremely fine-grained multiphase hard coatings with excellent tribological and corrosion behavior, thus offering new applications in the coating of engineering components. Because of their distinct colorations, some of the hexaborides of rare-earth elements may be used as decorative coatings on consumer products like wristwatch casings or eyeglass frames. Another promising field is the development of thermionic coatings based on rare-earth hexaborides, which may offer the possibility of the production of inexpensive and simple high emission filaments.

Mitterer, Christian

1997-10-01

270

Deformation behavior of metallic glass thin films  

NASA Astrophysics Data System (ADS)

We report room-temperature deformation behavior of damage-free metallic glass films characterized by nanoindentation and atomic force microscopy. The glass films with thicknesses ranging from 5 ?m down to ˜60 nm plastically deform by shear bands when subjected to both spherical and sharp Berkovich indenters. Importantly, we found that gallium contamination from focus ion beam (FIB) milling significantly suppresses shear band formation, indicating that the absence of shear bands in FIB milled samples may be caused by gallium irradiation damage, rather than sample size effect. Finite element simulation reveals that a high stress gradient at the film/substrate interface promotes the plastic deformation of the thin films but does not give rise to significant strain inhomogeneity.

Liu, Y. H.; Zhao, F.; Li, Y. L.; Chen, M. W.

2012-09-01

271

Optical properties of multilayer thin films  

SciTech Connect

Thin films composed of alternating layers of barium titanate (BaTiO{sub 3}) and silica (SiO{sub 2}), as well as alternating layers of tin dioxide (SnO{sub 2}) and silica (SiO{sub 2}) have been fabricated by the sol-gel technique. An automatic dip-coating and heating apparatus was built to coat and fire films of up to 30 layers. The cycles were adjustable and time-controlled. Scanning electron microscopy (SEM) of the films confirmed the multilayer structures of the coatings. Transmission spectra of SnO{sub 2}/SiO{sub 2} films were affected by the application of an applied electrical field.

Wu, Q.; Xu, Y.; Park, S.S. [Univ. of California, Los Angeles, CA (United States)] [and others

1995-12-31

272

A Multilayered Thin Film Insulator for Harsh Environments  

NASA Technical Reports Server (NTRS)

The status of work to develop a reliable high temperature dielectric thin film for use with thin film sensors is presented. The use of thin films to electrically insulate thin film sensors on engine components minimizes the intrusiveness of the sensor and allows a more accurate measurement of the environment. A variety of insulating films were investigated for preventing electrical shorting caused by insulator failure between the sensor and the component. By alternating layers of sputtered high temperature ceramics, a sequence of insulating layers was devised that prevents pinholes from forming completely through the insulator and maintains high electrical resistivity at high temperatures. The major technical challenge remaining is to optimize the fabrication of the insulator with respect to composition to achieve a reliable high temperature insulating film. Data from the testing of various potentially insulating thin film systems is presented and their application to thin film sensors is also discussed.

Wrbanek, John D.; Fralick, Gustave C.; Blaha, Charles A.; Busfield, A. Rachel; Thomas, Valarie D.

2002-01-01

273

Water\\/oil\\/water thin films: construction and applications  

Microsoft Academic Search

With the classical “thin-film balance” apparatus, one can study the properties of thin soap films (air\\/water\\/air films). Here,\\u000a we present a new version of that apparatus allowing us to build a single thin oil film horizontally held on a frame and completely\\u000a immersed in water. The frame used here is a glass frit: to make it suitable for holding oil

Arnaud Saint-Jaimes; Thomas Zemb; Dominique Langevin

274

Photovoltaic Properties of Thin Polymer (PVK-TNF) Films  

NASA Astrophysics Data System (ADS)

The photovoltaic properties of thin films of the polyvinylcarbazole-trinitrofluorenone complex are investigated. Thin films of thickness between 10 and 500 nm were formed by the solution-casting method. The photovoltaic energy conversion efficiency was measured in Au-(polymer thin film)-Al cells as a function of the film thickness, and it became a maximum (about 0.01%) at a thickness of about 100 nm.

Yamashita, Ken; Suzuki, Tatsuya; Hino, Taro

1982-10-01

275

Multicoloured electrochromic thin films of NiO\\/PANI  

Microsoft Academic Search

NiO\\/polyaniline (PANI) thin films have been prepared by a two-step process. NiO thin films were electrodeposited from an aqueous solution of NiCl2 · 6H2O at pH 7.5 on fluorine-doped tin oxide coated glass substrates and a layer of PANI was formed on NiO thin films by chemical bath deposition. The films were characterized for their structural, optical, morphological and electrochromic

A C Sonavane; A I Inamdar; H P Deshmukh; P S Patil

2010-01-01

276

Thermal conductivities of thin, sputtered optical films  

SciTech Connect

The normal component of the thin film thermal conductivity has been measured for the first time for several advanced sputtered optical materials. Included are data for single layers of boron nitride (BN), aluminum nitride (AIN), silicon aluminum nitride (Si-Al-N), silicon aluminum oxynitride (Si-Al-O-N), silicon carbide (SiC), and for dielectric-enhanced metal reflectors of the form Al(SiO{sub 2}/Si{sub 3}N{sub 4}){sup n} and Al(Al{sub 2}O{sub 3}/AIN){sup n}. Sputtered films of more conventional materials like SiO{sub 2}, Al{sub 2}O{sub 3}, Ta{sub 2}O{sub 5}, Ti, and Si have also been measured. The data show that thin film thermal conductivities are typically 10 to 100 times lower than conductivities for the same materials in bulk form. Structural disorder in the amorphous or very fine-grained films appears to account for most of the conductivity difference. Conclusive evidence for a film/substrate interface contribution is presented.

Henager, C.H. Jr.; Pawlewicz, W.T.

1991-05-01

277

Electrohydrodynamic instabilities in thin liquid trilayer films  

Experiments by Dickey et al. [Langmuir, 22, 4315 (2006)] and Leach et al. [Chaos, 15, 047506 (2005)] show that novel pillar shapes can be generated from electrohydrodynamic instabilities at the interfaces of thin polymer/polymer/air trilayer films. In this paper, we use linear stability analysis to investigate the effect of free charge and ac electric fields on the stability of trilayer systems. Our work is also motivated by our recent theoretical study [J. Fluid Mech., 631, 255 (2009)] which demonstrates how ac electric fields can be used to increase control over the pillar formation process in thin liquid bilayer films. For perfect dielectric films, the effect of an AC electric field can be understood by considering an equivalent DC field. Leaky dielectric films yield pillar configurations that are drastically different from perfect dielectric films, and AC fields can be used to control the location of free charge within the trilayer system. This can alter the pillar instability modes and generate smaller diameter pillars when conductivities are mismatched. The results presented here may be of interest for the creation of complex topographical patterns on polymer coatings and in microelectronics.

Roberts, Scott A. [Sandia National Lab., Albuquerque, NM (United States); Kumar, Satish [Univ. of Minnesota, Minneapolis, MN (United States)

2010-09-12

278

Thin Film...Large Payoff  

NASA Technical Reports Server (NTRS)

SRS Technologies is currently the only company licensed by Langley Research Center to produce colorless polyimides. They currently produce two polyimides, the LaRC-CP1 and LaRC-CP2 developed by Langley Research Center. These polyimides offer many advantages over other commercially available materials including excellent thermal stability, radiation resistance, solubility, and transparency. The SRS polyimides can be used in laminates, films, molded parts, and stock shapes. The polyimide technology has also helped the company further their development of solar arrays.

1998-01-01

279

Graphene growth on polycrystalline Ru thin films  

NASA Astrophysics Data System (ADS)

Monolayer graphene has been grown on polycrystalline Ru thin films on SiO2/Si substrates. The Ru films have columnar structure with strongly aligned grains exposing flat (0001) surface facets. Adjacent grains show small relative tilts of their [0001] axes and variations in in-plane orientation. Graphene layers grown on this template cover the entire surface and have uniform monolayer thickness. Analysis of the graphene/Ru moiré structure shows that monocrystalline graphene domains are coherent across a large number of substrate grains. Hence, the size of monolayer graphene domains is not limited by grain boundaries in the metal template.

Sutter, E.; Albrecht, P.; Sutter, P.

2009-09-01

280

Silver nanowire composite thin films as transparent electrodes for Cu(In,Ga)Se?/ZnS thin film solar cells.  

PubMed

Solution processed silver nanowire indium-tin oxide nanoparticle (AgNW-ITONP) composite thin films were successfully applied as the transparent electrodes for Cu(In,Ga)Se? (CIGS) thin film solar cells with ZnS buffer layers. Properties of the AgNW-ITONP thin film and its effects on performance of CIGS/ZnS thin film solar cells were studied. Compared with the traditional sputtered ITO electrodes, the AgNW-ITONP thin films show comparable optical transmittance and electrical conductivity. Furthermore, the AgNW-ITONP thin film causes no physical damage to the adjacent surface layer and does not need high temperature annealing, which makes it very suitable to use as transparent conductive layers for heat or sputtering damage-sensitive optoelectronic devices. By using AgNW-ITONP electrodes, the required thickness of the ZnS buffer layers for CIGS thin film solar cells was greatly decreased. PMID:24922214

Tan, Xiao-Hui; Chen, Yu; Liu, Ye-Xiang

2014-05-20

281

Nitrogen doped zinc oxide thin film  

SciTech Connect

To summarize, polycrystalline ZnO thin films were grown by reactive sputtering. Nitrogen was introduced into the films by reactive sputtering in an NO{sub 2} plasma or by N{sup +} implantation. All ZnO films grown show n-type conductivity. In unintentionally doped ZnO films, the n-type conductivities are attributed to Zn{sub i}, a native shallow donor. In NO{sub 2}-grown ZnO films, the n-type conductivity is attributed to (N{sub 2}){sub O}, a shallow double donor. In NO{sub 2}-grown ZnO films, 0.3 atomic % nitrogen was found to exist in the form of N{sub 2}O and N{sub 2}. Upon annealing, N{sub 2}O decomposes into N{sub 2} and O{sub 2}. In furnace-annealed samples N{sub 2} redistributes diffusively and forms gaseous N{sub 2} bubbles in the films. Unintentionally doped ZnO films were grown at different oxygen partial pressures. Zni was found to form even at oxygen-rich condition and led to n-type conductivity. N{sup +} implantation into unintentionally doped ZnO film deteriorates the crystallinity and optical properties and leads to higher electron concentration. The free electrons in the implanted films are attributed to the defects introduced by implantation and formation of (N{sub 2}){sub O} and Zni. Although today there is still no reliable means to produce good quality, stable p-type ZnO material, ZnO remains an attractive material with potential for high performance short wavelength optoelectronic devices. One may argue that gallium nitride was in a similar situation a decade ago. Although we did not obtain any p-type conductivity, we hope our research will provide a valuable reference to the literature.

Li, Sonny X.

2003-12-15

282

Growth of epitaxial thin films by pulsed laser ablation  

SciTech Connect

High-quality, high-temperature superconductor (HTSc) films can be grown by the pulsed laser ablation (PLA) process. This article provides a detailed introduction to the advantages and curent limitations of PLA for epitaxial film growth. Emphasis is placed on experimental methods and on exploitation of PLA to control epitaxial growth at either the unit cell or the atomic-layer level. Examples are taken from recent HTSc film growth. 33 figs, 127 refs. (DLC)

Lowndes, D.H.

1992-01-01

283

Growth of epitaxial thin films by pulsed laser ablation  

SciTech Connect

High-quality, high-temperature superconductor (HTSc) films can be grown by the pulsed laser ablation (PLA) process. This article provides a detailed introduction to the advantages and curent limitations of PLA for epitaxial film growth. Emphasis is placed on experimental methods and on exploitation of PLA to control epitaxial growth at either the unit cell or the atomic-layer level. Examples are taken from recent HTSc film growth. 33 figs, 127 refs. (DLC)

Lowndes, D.H.

1992-10-01

284

Superconducting epitaxial thin films of CeNi{sub x}Bi{sub 2} with a bismuth square net structure  

SciTech Connect

We have grown highly epitaxial and phase pure thin films of the arsenic-free pnictide compound CeNi{sub x}Bi{sub 2} on (100) MgO substrates by reactive molecular beam epitaxy (RMBE). X-ray diffraction and reflection high-energy electron diffraction of the films confirm the ZrCuSiAs structure with a Bi square net layer. Superconductivity was observed in magnetization and resistivity measurements for x= 0.75 to 0.93 in these CeNi{sub x}Bi{sub 2} thin films with the highest critical temperature of 4.05 K and a resistive transition width of 0.1 K for x= 0.86. Our results indicate that thin film deposition by RMBE provides a tool to synthesize high-quality pnictide superconductors of the novel 112 type.

Buckow, Alexander; Kupka, Katharina; Retzlaff, Reiner; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

2012-10-15

285

Modification and nano-patterning of high-Tc superconducting thin films by masked ion beam irradiation  

NASA Astrophysics Data System (ADS)

Ion irradiation of the high-temperature superconductor (HTS) YBa2Cu3O7 (Y-123) creates different types of defects depending on ion mass, energy and dose. Irradiation with helium ions of moderate energy (75 keV) primarily creates point defects. We measure in situ the modification of electrical transport properties of Y-123 thin films (thickness 310 nm) during ion irradiation. The He ions penetrate thin films and produce collision cascades with small lateral straggle that allow for patterning of nanostructures in the HTS layer. We present features smaller than 100 nm in size produced by masked ion beam irradiation of Y-123 films. Computer simulations indicate that nano-patterning of Y-123 thin films with 10 nm lateral resolution is achievable.

Bodea, M. A.; Pedarnig, J. D.; Siraj, K.; Behbood, N.; Bäuerle, D.; Lang, W.; Hasenfuss, C.; Palmetshofer, L.; Haselgrübler, K.; Kolarova, R.; Bauer, P.

2010-06-01

286

Substrate heater for thin film deposition  

DOEpatents

A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

Foltyn, Steve R. (111 Beryl St., Los Alamos, NM 87544)

1996-01-01

287

Atomic hydrogen adsorption on thin gold films  

NASA Astrophysics Data System (ADS)

Hydrogen adsorbate forms arising on thin gold films upon interaction with atomic hydrogen at 78 K have been studied by means of TDMS (thermal desorption mass spectrometry) and by determination of the adsorption rate. At low coverage (? ? 0.01) hydrogen adspecies characterized by an activation energy of desorption Ed = 57 kJ/mol have been found. At higher coverages a weakly adsorbed hydrogen species is formed (Ed = 54-33 kJ/mol). Examination of the adsorption kinetics indicates that this process is accompanied by recombination via the Eley-Rideal mechanism. Initial sticking probability for atomic hydrogen on the thin gold film surface at 78 K has been estimated to be ˜ 6 × 10-3.

Stobi?ski, L.; Du?, R.

1992-05-01

288

Defect formation in oxide thin films  

NASA Astrophysics Data System (ADS)

In nanosecond laser damage investigations, the specific defect density in the optical component or thin film plays the key role in triggering optical breakdown. UV irradiation can induce additional defects in optical materials before the damaging event takes place. This increased defect density can even be the main cause for UV laser damage as shown before in fused silica. Moving on to oxide thin films, this contribution will present studies on SiO2, Al2O3, and HfO2 ion beam sputtered coatings. Pure material single layers as well as composite material single layers comprised of two oxides have been investigated concerning their tendency to generate additional defects resulting from UV laser irradiation. Within this work, tests at 355 nm and 266 nm have been performed and are compared.

Jensen, Lars O.; Wagner, Frank; Mende, Mathias; Gouldieff, Céline; Blaschke, Holger; Natoli, Jean-Yves; Ristau, Detlev

2011-12-01

289

Thin film strain gage development program  

NASA Technical Reports Server (NTRS)

Sputtered thin-film dynamic strain gages of 2 millimeter (0.08 in) gage length and 10 micrometer (0.0004 in) thickness were fabricated on turbojet engine blades and tested in a simulated compressor environment. Four designs were developed, two for service to 600 K (600 F) and two for service to 900 K (1200 F). The program included a detailed study of guidelines for formulating strain-gage alloys to achieve superior dynamic and static gage performance. The tests included gage factor, fatigue, temperature cycling, spin to 100,000 G, and erosion. Since the installations are 30 times thinner than conventional wire strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain measurement accuracy higher than that attained with conventional gages is expected. The low profile and good adherence of the thin film elements is expected to result in improved durability over conventional gage elements in engine tests.

Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.

1983-01-01

290

Domain switching of fatigued ferroelectric thin films  

NASA Astrophysics Data System (ADS)

We investigate the domain wall speed of a ferroelectric PbZr0.48Ti0.52O3 (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue.

Tak Lim, Yun; Yeog Son, Jong; Shin, Young-Han

2014-05-01

291

Optimizing absorptance in nanostructured thin films  

NASA Astrophysics Data System (ADS)

To construct a solar cell with maximal efficiency it is necessary to minimise the remittances of the cell across the solar spectrum. Thin-film solar cells allow for production of solar cells with reduced cost, weight and rare mineral consumption; furthermore, engineering at the nanoscale may achieve the high levels of solar absorption attainable with traditional, thicker cells. Columnar thin films (CTFs) have the potential to fulfil these requirements, as by infiltrating the voids between the column with a fluid and by tailoring the shape of the columns, the optical properties can be tuned. Here we present a mathematical framework for calculating the absorptance of such an infiltrated CTF. Also presented are some preliminary numerical results, based on a titanium oxide CTF. These simulations imply that by decreasing the columnar angle (the angle between the column and the substrate) much higher levels of absorption can be achieved, as compared to a CTF with columns oriented normal to the substrate.

Anderson, Tom H.; Mackay, Tom G.

2013-09-01

292

Transport measurements on a thin Nb film with square array of nanoscale magnetic dots.  

NASA Astrophysics Data System (ADS)

Transport measurements (R vs. T, R vs. B, and V-I characteristics) were made on a thin Nb film deposited on top of a square array of nanoscale magnetic dots [1]. These measurements established that in many ways this system behaved like a Josephson junction array (JJA). We hypothesized that the stray magnetic field of the dots reduced the superconductivity in the Nb film in such a way as to make the film a superconductor-weaker superconductor-superconductor (S-S-S) JJA. Studies of the VIs in the presence of a radio frequency (rf) signal revealed the appearance of Shapiro steps in the VI's. The voltage location at which the steps occurred follow the Josephson relation Vn=n*N*(h/2)*?, where n=1,2,3, etc, N is the number of junctions along the current direction, and ? is the frequency of the rf signal. Sample provided by Dr. Axel Hoffmann from Argonne National Laboratory and Dr. Ivan K. Schuller from UCSD. [1] J. I. Martin, Y. Jaccard, A. Hoffmann, J. Nogues, J. M. George, J. I. Vicent, and I. K. Schuller, J. Appl. Physics. 84, 411 (1998)

Gómez, Luis B.; Mast, David B.

2002-03-01

293

Thin films for optical systems; Proceedings of the Meeting, Berlin, Germany, Sept. 14-18, 1992  

Microsoft Academic Search

These proceedings discuss the theory and design of optical thin films, practical problems and solutions in coating manufacture, thin films for electrooptical and infrared applications, thin-film characterization, optical thin films for communication systems, thin films for excimer and high-power lasers, thin films for optical data storage, and optical-coating design problem and solutions. Papers are presented on thin films for magnetooptical

Karl H. Guenther

1993-01-01

294

Stability and dewetting of thin liquid films  

E-print Network

The stability of thin liquid coatings is of fundamental interest in every- day life. Homogeneous and non-volatile liquid coatings may dewet either by heterogeneous nucleation, thermal nucleation, or spinodal dewetting. Wetting and dewetting is explained on a fundamental level, including a discussion of relevant interactions. The article will also address the various dewetting scenarios and explain how the effective interface potential governs the behavior obtained for various stratified substrates and film thicknesses.

Karin Jacobs; Ralf Seemann; Stephan Herminghaus

2008-05-28

295

Stable localized patterns in thin liquid films  

NASA Technical Reports Server (NTRS)

We study a 2-D nonlinear evolution equation which describes the 3-D spatiotemporal behavior of the air-liquid interface of a thin liquid film lying on the underside of a cooled horizontal plate. We show that the Marangoni effect can stabilize the destabilizing effect of gravity (the Rayleigh-Taylor instability) allowing for the existence of stable localized axisymmetric solutions for a wide range of parameter values. Various properties of these structures are discussed.

Deissler, Robert J.; Oron, Alexander

1991-01-01

296

Dynamic susceptibility computations for thin magnetic films  

NASA Astrophysics Data System (ADS)

This paper deals with the dynamic modelling of thin ferromagnetic layers, based on the coupling of Maxwell's equations with the nonlinear Landau-Lifschitz-Gilbert law. A 2-D micromagnetic model is described which involves a FDTD code to determine equilibrium configurations and a finite element method to compute magnetostatic fields. Finally, after linearization, the susceptibility spectra of films supporting a weak-stripe-domain structure are computed and successfully compared to existing measurements without introducing any fitting parameter.

Vacus, Olivier; Vukadinovic, Nicolas

2005-04-01

297

Phonon emission spectra of thin metallic films  

Microsoft Academic Search

Thin metallic films evaporated on an Al2O3-single crystal and cooled to liquid helium temperatures are heated by short electric current pulses. The high frequency part\\u000a of the emitted phonons is detected by calibrated superconductive tunneling junctions on the opposite surface of the substrate.\\u000a The observed phonon detector signal amplitude is compared with theoretical models taking account of the boundary conditions

Wolfgang Frick; Dieter Waldmann; Wolfgang Eisenmenger

1975-01-01

298

Thermal conductivities of thin, sputtered optical films  

SciTech Connect

The normal component of thin-film thermal conductivity has been measured for the first time, to the best of our knowledge, for several advanced sputtered optical materials. Included are data for single layers of boron nitride, silicon aluminum nitride, silicon aluminum oxynitride, silicon carbide, and for dielectric-enhanced metal reflectors of the form Al(SiO[sub 2]/Si[sub 3]N[sub 4])[sup [ital n

Henager, C.H. Jr.; Pawlewicz, W.T. (Pacific Northwest Laboratories, Battelle Memorial Institute, Battelle Boulevard, P.O. Box 999, Richland, Washington 99352 (United States))

1993-01-01

299

Packaging material for thin film lithium batteries  

DOEpatents

A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.

Bates, John B. (116 Baltimore Dr., Oak Ridge, TN 37830); Dudney, Nancy J. (11634 S. Monticello Rd., Knoxville, TN 37922); Weatherspoon, Kim A. (223 Wadsworth Pl., Oak Ridge, TN 37830)

1996-01-01

300

Thin Film Sensors for Surface Measurements  

NASA Technical Reports Server (NTRS)

Advanced thin film sensors that can provide accurate surface temperature, strain, and heat flux measurements have been developed at NASA Glenn Research Center. These sensors provide minimally intrusive characterization of advanced propulsion materials and components in hostile, high-temperature environments as well as validation of propulsion system design codes. The sensors are designed for applications on different material systems and engine components for testing in engine simulation facilities. Thin film thermocouples and strain gauges for the measurement of surface temperature and strain have been demonstrated on metals, ceramics and advanced ceramic-based composites of various component configurations. Test environments have included both air-breathing and space propulsion-based engine and burner rig environments at surface temperatures up to 1100 C and under high gas flow and pressure conditions. The technologies developed for these sensors as well as for a thin film heat flux gauge have been integrated into a single multifunctional gauge for the simultaneous real-time measurement of surface temperature, strain, and heat flux. This is the first step toward the development of smart sensors with integrated signal conditioning and high temperature electronics that would have the capability to provide feedback to the operating system in real-time. A description of the fabrication process for the thin film sensors and multifunctional gauge will be provided. In addition, the material systems on which the sensors have been demonstrated, the test facilities and the results of the tests to-date will be described. Finally, the results will be provided of the current effort to demonstrate the capabilities of the multifunctional gauge.

Martin, Lisa C.; Wrbanek, John D.; Fralick, Gustave C.

2001-01-01

301

Integrated radioactive thin films for sensing systems  

Microsoft Academic Search

Hybrid electromechanical systems with integrated power supplies are made possible with radioisotope thin films. A self-powered pressure transducer with pulsed radiofrequency (RF) output and a nanopower betavoltaic microbattery suitable for low-power CMOS are demonstrated in this paper. The pressure transducer collects charges emitted from the radioisotope with a dielectric cantilever to realize a self-reciprocating process, whose period is modulated by

Amit Lal; Hui Li; Hang Guo

2004-01-01

302

Structures for dense, crack free thin films  

DOEpatents

The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

2011-03-08

303

Electrodeposition of CdTe thin films  

Microsoft Academic Search

Cadmium telluride thin films were fabricated on Ti and Nesatron substrates by electrodeposition and characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analyses (EDAX), optical transmission measurements, and photoelectrochemical (PEC) studies. The deposition-bath preparation procedure was slightly modified from the literature method to permit initial speciation of TeOâ and thereby increase the loading level of Te in the

R. N. Bhattachurya; K. Rajeshwar

1984-01-01

304

Thin-film optical shutter. Final report  

SciTech Connect

A specific embodiment of macroconjugated macromolecules, the poly (p-phenylene)'s, has been chosen as the one most likely to meet all of the requirements of the Thin Film Optical Shutter project (TFOS). The reason for this choice is included. In order to be able to make meaningful calculations of the thermodynamic and optical properties of the poly (p-phenylene)'s a new quantum mechanical method was developed - Equilibrium Bond Length (EBL) Theory. Some results of EBL Theory are included.

Matlow, S.L.

1981-02-01

305

Fabrication of ZnO thin film transistors by atomic force microscopy nanolithogrophy through zinc thin films  

Microsoft Academic Search

Zinc oxide (ZnO) thin film transistors were fabricated by local anodic oxidation (LAO) of polycrystalline zinc film using an atomic force microscope (AFM). Nanometer-thin zinc film can be locally transformed into p -type zinc oxide by an anodic oxidation technique using an AFM at room temperature. With this fabrication process, we have fabricated a backgate, Schottky-barrier-contact type thin film ZnO

Jeff T. H. Tsai; Ben H. B. Lee; Ming S. Yang

2009-01-01

306

Preparation and characterization of ZnO thin films prepared by thermal oxidation of evaporated Zn thin films  

Microsoft Academic Search

In this paper, the experimental results regarding some structural, electrical and optical properties of ZnO thin films prepared by thermal oxidation of metallic Zn thin films are presented.Zn thin films (d=200–400 nm) were deposited by thermal evaporation under vacuum, onto unheated glass substrates, using the quasi-closed volume technique. In order to obtain ZnO films, zinc-coated glass substrates were isochronally heated in

G. G. Rusu; Mihaela G?rtan; M. Rusu

2007-01-01

307

Fabrication of ZnO thin film transistors by atomic force microscopy nanolithogrophy through zinc thin films  

Microsoft Academic Search

Zinc oxide (ZnO) thin film transistors were fabricated by local anodic oxidation (LAO) of polycrystalline zinc film using an atomic force microscope (AFM). Nanometer-thin zinc film can be locally transformed into p-type zinc oxide by an anodic oxidation technique using an AFM at room temperature. With this fabrication process, we have fabricated a backgate, Schottky-barrier-contact type thin film ZnO transistor.

J. T. H. Tsai; Ben H. B. Lee; Ming S. Yang

2009-01-01

308

Instability of Viscoelastic Thin Films, and Applications  

NASA Astrophysics Data System (ADS)

An ion beam bombarding a solid surface has been long been known to produce an instability leading to a modulated surface (with ripples or dots); though the basic mechanisms for this instability remain under considerable debate. During our investigation of this problem, we have been led to a basic problem in thin film fluid mechanics: the instability of a viscoelastic thin film that is under compressive stress. This applies to the ion bombarded problem because there is evidence that the ion beam fluidizes a thin viscoelastic layer, and that this layer is then stressed by the ion beam. By varying the ratio of the shear modulus to the viscosity, we analyze this problem and connect the known limits of a stressed elastic solid film or a surface-tension driven lubrication flow. In particular, we identify the presence or absence of a surface instability as a function of these two parameters. We discuss the application of this model to the surface layer of an ion-sputtered target; and also discuss its potential application to the wrinkling instability of a growing biofilm attached to a substrate.

Norris, Scott; Aziz, Michael; Brenner, Michael

2009-11-01

309

Comparison of the pinning energy in Fe(Se1-xTex) compound between single crystals and thin films  

NASA Astrophysics Data System (ADS)

Among the families of iron-based superconductors, we investigate flux pinning mechanisms in the Fe(Se1-xTex) compound. We perform magneto-resistance and current-voltage measurements on single-crystals, as well as on several epitaxial thin films grown on different substrates (CaF2, LaAlO3). The activation energy is derived as a function of magnetic field, U(H). The influence of magnetic field orientation on the pinning energy activation mechanism is also studied, leading to the anisotropy analysis which reveals low anisotropy in thin films grown on CaF2 substrate with respect to single crystals and films grown on LaAlO3. Concerning the dominant pinning regime, the exponents of the power law dependence U0(H) ~ H-? have been evaluated, confirm that weak pinning is a general characteristic of this compound. The single exponent feature, generally noticed on thin films grown on SrTiO3 substrate and associated to a strong single vortex regime, has been observed in thin films grown on LaAlO3, only in the parallel configuration. At the end, this overall comparison can be useful to develop a technological material able to compete with high temperature superconductors.

Leo, A.; Guarino, A.; Grimaldi, G.; Nigro, A.; Pace, S.; Bellingeri, E.; Kawale, S.; Ferdeghini, C.; Giannini, E.

2014-05-01

310

1260 IEEE TRANSACTIONSON APPLIED SUPERCONDUCTIVITY, VOL. 7, NO. 2, JUNE 1997 Nonlinear Response of HTSC Thin Film Microwave Resonators in an  

E-print Network

of HTSC Thin Film Microwave Resonators in an Applied DC Magnetic Field Durga P. Choudhurya". Balain A performance. I. INTRODUCTION 'The microwave response of high-T, superconductors (HTSC) is important both from the point, of view of microwave applications of HTSC[l] and fundamental physics[2]. An understanding

Sridhar, Srinivas

311

Stabilization mechanism of electrodeposited silicon thin films.  

PubMed

Amorphous composite silicon thin films electrodeposited in tetrahydrofuran, containing up to 80 at% of Si and exhibiting an homogeneous dispersions of O, C and Cl in the amorphous Si matrix, have been successfully stabilized against oxidation using a post-annealing step in inert atmosphere. In order to understand the impact of the annealing step on their stabilization against oxidation, their composition and structure have been investigated upon heat treatments. It has been shown that the presence of impurities such as O, C and Cl does not have any impact on the stabilization process, which is rather linked to the presence of hydrogen in the Si composites. This conclusion has been drawn after a detailed analysis of the bonding structure of films annealed at different temperatures and dwell times by the mean of Raman spectroscopy. It has been shown that annealing the as-deposited films at 350 °C for a couple of hours or at higher temperatures induced a hydrogen evolution, characterized by the breaking of Si-H bonds and the formation of Si-Si bonds, which stabilized the silicon network. The understanding and the reproducibility of this stabilization process of silicon thin film electrodeposited in organic solvent paves the way for their use for many applications. PMID:25212513

Vichery, C; Le Nader, V; Frantz, C; Zhang, Y; Michler, J; Philippe, L

2014-09-24

312

The preparation, characterization, and application of thin film devices  

Microsoft Academic Search

This thesis deals with the preparation of two thin film devices, in particular a nitrogen dioxide (NOsb2) gas sensor and a rechargeable lithium battery. A number of different thin film preparation techniques were used for a variety of applications and the resultant films were characterized by spectroscopic and electrochemical methods. The NOsb2 gas sensor was based on Langmuir-Blodgett (LB) monolayer

Bob Berno

1997-01-01

313

Fabrication and transport properties of thin films of quasicrystals  

Microsoft Academic Search

We present a brief overview of the preparation of quasicrystalline thin films, emphasising the constraints and methods used to prepare stable ternary quasicrystal films. As an example, we present the preparation of thin i-Al–Cu–Fe and i-Al–Pd–Re films and the study of dimensionality effects in the electrical conductivity.

T Grenet; F Giroud; K Loubet; A Bergman; G Safran; J Labar; P Barna; J. L Joulaud; M Capitan

2002-01-01

314

Thermionic vacuum arc (TVA) technique for magnesium thin film deposition  

Microsoft Academic Search

In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high

M. Z. Balbag; S. Pat; M. Ozkan; N. Ekem; G. Musa

2010-01-01

315

Structure in thin superfluid helium films  

SciTech Connect

Precision measurements of third sound in atomically thin {sup 4}He films on Ne, Ar, and CO{sub 2} substrates reveal a periodic structure not corresponding to whole layers. Treating the He film as an incompressible, continuous fluid, the data indicate that the chemical potential has a contribution proportional to {ell}{sup {minus}6}, where {ell} is the He coverage in layers, which is modulated at intervals of 0.62{plus minus}0.04 layers and which weakens the van der Waals potential. Alternatively the data indicates the existence in the film of a damped smectic density wave with a 0.54{plus minus}0.40 layer periodicity.

Shirron, P.J.; Gillis, K.A.; Mochel, J.M. (Univ. of Illinois at Urbana-Champaign (USA))

1990-02-01

316

Electron-tunneling studies of thin films of high-Tc superconducting La-Sr-Cu-O  

Microsoft Academic Search

The paper presents the results of the study of electron tunneling into thin films of the new high-Tc superconductor La-Sr-Cu-O. Both sandwich-type tunneling with a Pb counterelectrode and point-contact tunneling have been successfully achieved. The results show exceptionally large energy gaps in these materials (roughly 20, 30, and possibly even 60 mV), larger than previously obtained on bulk sintered powders.

M. Naito; D. P. E. Smith; M. D. Kirk; B. Oh; M. R. Hahn; K. Char; D. Mitzi; J. Sun; D. Webb; M. Beasley; O. Fischer; T. Geballe; R. Hammond; A. Kapitulnik; C. Quate

1987-01-01

317

Specific heat measurement set-up for quench condensed thin superconducting films.  

PubMed

We present a set-up designed for the measurement of specific heat of very thin or ultra-thin quench condensed superconducting films. In an ultra-high vacuum chamber, materials of interest can be thermally evaporated directly on a silicon membrane regulated in temperature from 1.4 K to 10 K. On this membrane, a heater and a thermometer are lithographically fabricated, allowing the measurement of heat capacity of the quench condensed layers. This apparatus permits the simultaneous thermal and electrical characterization of successively deposited layers in situ without exposing the deposited materials to room temperature or atmospheric conditions, both being irreversibly harmful to the samples. This system can be used to study specific heat signatures of phase transitions through the superconductor to insulator transition of quench condensed films. PMID:24880383

Poran, Shachaf; Molina-Ruiz, Manel; Gérardin, Anne; Frydman, Aviad; Bourgeois, Olivier

2014-05-01

318

Superconducting YBaCuO thin films by Cu-ion implantation  

SciTech Connect

We have investigated the fabrication of thin-film superconductors by Cu-ion implantation into initially Cu-deficient Y(BaF{sub 2})Cu thin films. The precursor films were co-evaporated on SrTiO{sub 3} substrates, and subsequently implanted to various doses with 400 keV {sup 63}Cu{sup 2+}. Implantations were preformed at both LN{sub 2} temperature, and at 380{degree}C. The films were post-annealed in oxygen, and characterized as a function of dose by four-point probe analysis, x-ray diffraction, ion-beam backscattering and channeling, and scanning electron microscopy. It was found that a significant improvement in film quality could be achieved by heating the films to 380{degree}C during the implantation. The best films became fully superconducting at 60--70 K, and exhibited good metallic R vs. T. behavior in the normal state. 14 refs., 2 figs., 1 tab.

Hubbard, K.M.; Bordes, N.; Nastasi, M.; Tesmer, J.R.

1990-01-01

319

Identification of pinning centres in high Tc superconducting thin films by AC susceptibility  

NASA Astrophysics Data System (ADS)

We compare vortex pinning properties of high temperature superconductors (HTS) thin films and correlate these to microstructure to identify pinning centres. We have grown YBa2Cu3O7- (YBCO), YBCO/PrBa2Cu2.8Ga0.2O7-? (YBCO/PBCGO), NdBa2Cu3O7-? (NBCO) thin films and superlattices on (100) SrTiO3. We show that pinning by intersections of twin boundaries usually dominates except for strained superlattices [1] and for the NBCO thin films presenting only one [1, 1, 0] twin variant (the [10] being completely eliminated), thereby drastically reducing the density of twin boundary intersections (TBI). As expected, AC susceptibility measurements show low pinning properties of these samples. Using High Resolution AC susceptibility, we have discriminated several mechanisms contributing to vortex pinning in a given sample. Indeed, when we eliminated TBI pinning in NBCO thin films, several peaks were observed in ?(T) curve, each one presumably associated with a specific pinning mechanism.

Crété, D.-G.; Bernard, R.; Pommereau, J.-H.; Gadois, C.; Berger, S.; Briatico, J.; Contour, J.-P.; Durand, O.; Maurice, J.-L.; Grollier, J.; Bouzehouane, K.

2004-05-01

320

Processing of magnetostrictive thin film devices  

NASA Astrophysics Data System (ADS)

(Tb,Dy)Fesb2 intermetallic alloys exhibit very large magnetostrictive strains. Alloys with composition near Tbsb{0.3}Dysb{0.7}Fesb2, known as Terfenol-D, are of particular interest because this is the composition where room temperature anisotropy compensation occurs and the moment can be easily rotated. Terfenol-D has a cubic Laves phase structure and exhibits maximum magnetostrictive strain along $ directions at room temperature. Bulk Terfenol-D tends to grow as twinned dendritic sheets with $ orientation. Recently, there has been increased interest in Terfenol-D thin film devices. Crystallographic texture can change the magnetostrictive properties of thin films. It is the purpose of this research to study the effect of postdeposition annealing and magnetic annealing treatments on the microstructure of Terfenol-D thin films. It is predicted that textured films can be obtained by exploiting increased magnetocrystalline anisotropy at elevated temperatures. This would improve the low field magnetostrictive strains attainable for device applications. Also of recent interest is the fabrication of magnetostrictive composites. Increased toughness and durability are attainable at the cost of reduced magnetostrictive performance. Terfenol-D composites have been made with polymers. Composites with metals would be stronger and tougher but conventional high temperature processing routes cause unwanted reactions. Temperatures high enough to allow appreciable diffusion for sintering would also allow the metal binder phase to interdiffuse with Terfenol-D. This work also examines the feasibility of explosive compaction of Terfenol-D-metal composites. The short duration, on the order of microseconds, of the pressure and temperature pulse experienced by the powder leads to compaction at near room temperature. This is expected to prevent unwanted reactions between Terfenol-D and the metal binder.

Loveless, Michael Ray

321

Semiconductor thin-film optical constant determination and thin-film thickness measurement equipment correlation  

NASA Astrophysics Data System (ADS)

There are several methods for correlating thin film thickness measurement equipment. The most commonly used method is to program in an offset that gets systematically added to or subtracted from the thickness calculation. Measurement errors can occur using this 'fudge factor' method because the relationship between the reference thicknesses and the measured thicknesses is not, in general, a fixed constant or simple function. A better method for correlating thin film thickness measurement equipment is to tune the instruments to the process by refining the internal optical constants.

Kaiser, Anne M.

1991-07-01

322

Anisotropic conductive film flip chip joining using thin chips  

Microsoft Academic Search

In this study, flip chip interconnections were made on very flexible polyethylene naphthalate substrates using anisotropic conductive film. Two kinds of chips were used: chips of normal thickness and thin chips. The thin chips were very thin, only 50 ?m thick. Due to the thinness of the chips they were flexible and the entire joint was bendable. The reliability properties

Erja Jokinen; Eero Ristolainen

2002-01-01

323

Study on mask technology of CVD diamond thin films by RIE etching  

Microsoft Academic Search

The patterning of diamond thin films by RIE etching must use hard mask. Ni and NiTi thin films are better candidate to be used as diamond mask based on mask selective ratio and patterning process. NiTi thin film mask has higher etching selective ratio than that of Ni thin film, Ni thin film plating through mask is applicable to small

Chunsheng Yang; Guifu Ding; Xiang Yao; Xiaolin Zhao

2000-01-01

324

Multilayer thin-film coatings for optical communication systems  

Microsoft Academic Search

Recent developments in thin-film coatings for optical communication systems are reviewed. Particular emphasis is given to thin-film designs with dispersion related to the photonic crystal superprism effect. A single dispersive coating may be used for multiplexing or demultiplexing several wavelength channels by spatial beam shifting. ?2004 Optical Society of America OCIS codes: (310.0310) Thin films, (060.2340) Fiber optics components; (260.2030)

Martina Gerken; David A. B. Miller

2004-01-01

325

Thin film magnetostrictive sensor with on-chip readout  

Microsoft Academic Search

We report the first successful integration of magnetostrictive Metglas2605S2 (Fesb{78}Sisb9Bsb{13}) thin film sensor system on silicon with high resolution capacitive readout. A deposition process for Metglas thin film has been developed to allow easy control of thin film composition. An amorphous microstructure has been achieved over a wide temperature range, and in-situ magnetic domain alignment can be accomplished at room

Yong Lu

1997-01-01

326

Tunable (LSMO) Ferromagnetic Thin Films for Radio Frequency Applications  

Microsoft Academic Search

In this letter, an original work in tunable (La,Sr)MnO3 (LSMO) ferromagnetic thin film materials for radio frequency applications is presented. 400 nm thick LSMO thin film is formed by the chemical solution deposition on the top of indium tin oxide (ITO)\\/SiO2\\/Si heterostructure. Interdigitated capacitor structures are used to study the behavior of LSMO thin film materials when a dc electrostatic

M. Al Ahmad; Young Taek Lee; Chae Il Cheon; Eui-Jung Yun; R. Plana

2009-01-01

327

Overview and Challenges of Thin Film Solar Electric Technologies  

SciTech Connect

In this paper, we report on the significant progress made worldwide by thin-film solar cells, namely, amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS). Thin-film photovoltaic (PV) technology status is also discussed in detail. In addition, R&D and technology challenges in all three areas are elucidated. The worldwide estimated projection for thin-film PV technology production capacity announcements are estimated at more than 5000 MW by 2010.

Ullal, H. S.

2008-12-01

328

Ellipsometric measurements for thin-film-based sensor systems  

NASA Astrophysics Data System (ADS)

The application of a highly birefringent fiber polarization modulation technique for ellipsometric measurements on sol-gel thin films is described. The ability of the system to determine the ellipsometric parameters of thin films is demonstrated. The system is then used to monitor the ellipsometric parameters of thin films on exposure to a perturbing environment of humidity and pressure. The potential of the system for application in chemical sensor systems is indicated and discussed.

Chitaree, Ratchapak; Murphy, V.; Weir, K.; Palmer, Andrew W.; Grattan, Kenneth T. V.; MacCraith, Brian D.

1995-09-01

329

Thin films of metal-organic frameworks.  

PubMed

The fabrication of thin film coatings of metal-organic frameworks (MOFs) on various substrates is discussed in this critical review. Interestingly, the relatively few studies on MOF films that have appeared in the literature are limited to the following cases: [Zn4O(bdc)3] (MOF-5; bdc=1,4-benzenedicarboxylate), [Cu3(btc)2] (HKUST-1; btc=1,3,5-benzenetricarboxylate), [Zn2(bdc)2(dabco)] (dabco=1,4-diazabicyclo[2.2.2]octane), [Mn(HCOO)], [Cu2(pzdc)2(pyz)] (CPL-1; pzdc=pyrazine-2,3-dicarboxylate, pyz=pyrazine), [Fe(OH)(bdc)] (MIL-53(Fe)) and [Fe3O(bdc)3(Ac)] (MIL-88B; Ac=CH3COO-). Various substrates and support materials have been used, including silica, porous alumina, graphite and organic surfaces, i.e. self-assembled monolayers (SAMs) on gold, as well as silica surfaces. Most of the MOF films were grown by immersion of the selected substrates into specifically pre-treated solvothermal mother liquors of the particular MOF material. This results in more or less densely packed films of intergrown primary crystallites of sizes ranging up to several microm, leading to corresponding film thicknesses. Alternatively, almost atomically flat and very homogenous films, with thicknesses of up to ca. 100 nm, were grown in a novel stepwise layer-by-layer method. The individual growth steps are separated by removing unreacted components via rinsing the substrate with the solvent. The layer-by-layer method offers the possibility to study the kinetics of film formation in more detail using surface plasmon resonance. In some cases, particularly on SAM-modified substrates, a highly oriented growth was observed, and in the case of the MIL-53/MIL-88B system, a phase selective deposition of MIL-88B, rather than MIL-53(Fe), was reported. The growth of MOF thin films is important for smart membranes, catalytic coatings, chemical sensors and related nanodevices (63 references). PMID:19384445

Zacher, Denise; Shekhah, Osama; Wöll, Christof; Fischer, Roland A

2009-05-01

330

Physical Properties of Thin Film Semiconducting Materials  

NASA Astrophysics Data System (ADS)

The physics and chemistry of semiconducting materials is a continuous question of debate. We can find a large stock of well-known properties but at the same time, many things are not understood. In recent years, porous silicon (PS-Si), diselenide of copper and indium (CuInSe2 or CIS) and metal oxide semiconductors like tin oxide (SnO2) and zinc oxide (ZnO) have been subjected to extensive studies because of the rising interest their potential applications in fields such as electronic components, solar panels, catalysis, gas sensors, in biocompatible materials, in Li-based batteries, in new generation of MOSFETS. Bulk structure and surface and interface properties play important roles in all of these applications. A deeper understanding of these fundamental properties would impact largely on technological application performances. In our laboratory, thin films of undoped and antimony-doped films of tin oxide have been deposited by chemical vapor deposition. Spray pyrolysis was used for ZnO. CIS was prepared by flash evaporation or close-space vapor transport. Some of the deposition parameters have been varied, such as substrate temperature, time of deposition (or anodization), and molar concentration of bath preparation. For some samples, thermal annealing was carried out under oxygen (or air), under nitrogen gas and under vacuum. Deposition and post-deposition parameters are known to strongly influence film structure and electrical resistivity. We investigated the influence of film thickness and thermal annealing on structural optical and electrical properties of the films. Examination of SnO2 by x-ray diffraction showed that the main films are polycrystalline with rutile structure. The x-ray spectra of ZnO indicated a hexagonal wurtzite structure. Characterizations of CIS films with compositional analysis, x-ray diffraction, scanning microscopy, spectrophotometry, and photoluminescence were carried out.

Bouras, N.; Djebbouri, M.; Outemzabet, R.; Sali, S.; Zerrouki, H.; Zouaoui, A.; Kesri, N.

2005-10-01

331

Spreading Resistance on Thin Film Contacts  

NASA Astrophysics Data System (ADS)

Electrical contact [1] is important to wire-array z-pinches, metal-insulator-vacuum junctions, and high power microwave sources, etc. Contact problems account for 40 percent of all electrical failures, from small scale consumer electronics to large scale defense and aerospace systems. The crowding of the current lines at contacts leads to enhanced localized heating, a measure of which is the spreading resistance (Rs). For a microscopic area of contact (the ``a-spot'' [1]) on a thin film, we calculate Rs in both Cartesian and cylindrical geometries [2]. In the limit of small film thickness, h, the normalized thin film spreading resistance converges to the finite values, 2.77 for the Cartesian case and 0.28 for the cylindrical case. These same finite limits are found to be applicable to the a-spot between bulk solids in the high frequency limit if the skin depth is identified with h. Extension to a general a-spot geometry is proposed [2]. [4pt] [1] R. Holm, Electric Contacts, 4th ed., Springer (1967). [0pt] [2] P. Zhang et al., IEEE Trans. Electron Devices 59, 1936 (2012).

Zhang, Peng; Lau, Y. Y.; Hung, D.; Gilgenbach, R. M.

2012-10-01

332

Wrinkling of Inhomogeneously Strained Thin Polymer Films  

NASA Astrophysics Data System (ADS)

Wrinkles occur due to a mechanical instability when sufficient strain is applied to an incompressible thin film attached to a deformable substrate. For wrinkles made with a polymer film supported on a soft elastomer, the amplitude is directly proportional to the wavelength and the square root of the applied strain. This dependence has been confirmed with ideal substrates where the global strain is homogeneously distributed, but the influence of strain inhomogeneity has not been considered previously. We use the contact line wrinkling technique to prepare polystyrene thin films with periodic regions of different wrinkle amplitudes, hence strains, on soft substrates. The surfaces with inhomogeneous wrinkle amplitudes and directions approach a homogeneous structure upon the application of sufficiently large strains. The surface becomes homogeneous at a relatively small strain due to the growth rate difference between pre-wrinkles and new wrinkles. Moreover, we find the pre-wrinkled region starts strain localizing prior to the initially flat region. We derive relationships to describe these processes, providing fundamental knowledge of the wrinkling mechanism.

Chen, Yu-Cheng; Crosby, Alfred J.

2013-03-01

333

Collective excitations in thin ^3He films  

NASA Astrophysics Data System (ADS)

The spectra for (longitudinal) collective excitations in thin polarized ^3He films are calculated from Fermi liquid theory. The calculation uses state-dependent Landau parameters that have been computed to quadratic order in s-wave and p-wave effective interaction components. The interaction components have been determined from existing spin susceptibility and specific heat measurements for ^3He adsorbed on graphite substrates and also in thin ^3He - superfluid ^4He films. The zero sound and spin-zero sound spectra as a function of density and polarization are obtained by solving Landau's kinetic equation. The matrix elements are computed exactly and analytically. The solutions contain partial wave contributions up to the l= 3 angular momentum components. In particular, we study features in the oscillation amplitudes of the two Fermi surfaces at finite polarization. We note that at this time there have been no direct measurements of sound speeds in ^3He films and so all of these results constitute predictions.

Li, David; Anderson, Roger; Miller, Michael

2011-10-01

334

PZT Thin Film Piezoelectric Traveling Wave Motor  

NASA Technical Reports Server (NTRS)

With the development of micro-electro-mechanical systems (MEMS), its various applications are attracting more and more attention. Among MEMS, micro motors, electrostatic and electromagnetic, are the typical and important ones. As an alternative approach, the piezoelectric traveling wave micro motor, based on thin film material and integrated circuit technologies, circumvents many of the drawbacks of the above mentioned two types of motors and displays distinct advantages. In this paper we report on a lead-zirconate-titanate (PZT) piezoelectric thin film traveling wave motor. The PZT film with a thickness of 150 micrometers and a diameter of 8 mm was first deposited onto a metal substrate as the stator material. Then, eight sections were patterned to form the stator electrodes. The rotor had an 8 kHz frequency power supply. The rotation speed of the motor is 100 rpm. The relationship of the friction between the stator and the rotor and the structure of the rotor on rotation were also studied.

Shen, Dexin; Zhang, Baoan; Yang, Genqing; Jiao, Jiwei; Lu, Jianguo; Wang, Weiyuan

1995-01-01

335

High- Tc thin-film magnetometer  

SciTech Connect

We have constructed and tested high-{Tc} magnetometers by coupling a high-{Tc} thin-film Superconducting QUantum Interference Device (SQUID) to two different high-{Tc} thin-film flux transformers. The SQUID was made from Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8+y} films grown on MgO, with junctions consisting of native grain boundaries. The flux transformers were made from YBa{sub 2}Cu{sub 3}O{sub 7-x}, and each had 10-turn input coils and a single-turn pickup loop. The first transformer, which was patterned with a combination of shadow masks and photolithography, yielded a magnetic field gain of about {minus}7.5, functioned up to 79 K, and gave a magnetic field sensitivity B{sub N} (10 Hz) {approx} 3.1 pT Hz{sup {minus}1/2}at 38 K. The second transformer, which was patterned entirely by photolithography, yielded a gain of about {minus}8.7, functioned up to 25 K, and had a sensitivity B{sub N} (10 Hz) {approx} 3.5 pT Hz{sup {minus}1/2} at 4.2 K. In both cases, the limiting noise arose in the SQUID. 10 refs., 5 figs., 1 tab.

Miklich, A.H.; Wellstood, F.C.; Kingston, J.J.; Clarke, J. (Lawrence Berkeley Lab., CA (USA)); Colclough, M.S. (Conductus, Inc., Sunnyvale, CA (USA)); Cardona, A.H.; Bourne, L.C.; Olson, W.L.; Eddy, M.M. (Superconductor Technologies, Inc., Santa Barbara, CA (USA))

1990-09-01

336

CCMR: Synthesis of Nanoporous Gold Thin Films  

NSDL National Science Digital Library

Starting with a gold alloy, it is possible to selectively etch away the non-gold element and obtain a tortuous porous network within the gold with pore widths ranging from just 20-4nm. The vast amount of void space makes for large surface areas of approximately 2 m²/g. This new material has found use in such applications as filters, biosensors, chemical catalysts, and ultra-capacitors. Through annealing, the size of these pores can be modified to fit the need of its particular application. Previous research has been done here at Cornell on nanoporous gold in the form of bulk films with of 200μm. However, the behavior of thin films of this material of just 200nm in thickness has not yet been studied extensively. The goal of this project was to come up with a way to create nanoporous gold thin films and to measure the effects of pore coarsening during annealing and the amount of silver remaining in the sample during the etching procedure.

Thiel, Andrew

2005-08-17

337

Thin-Film Photovoltaics: Status and Applications to Space Power  

NASA Technical Reports Server (NTRS)

The potential applications of thin film polycrystalline and amorphous cells for space are discussed. There have been great advances in thin film solar cells for terrestrial applications; transfer of this technology to space applications could result in ultra low weight solar arrays with potentially large gains in specific power. Recent advances in thin film solar cells are reviewed, including polycrystalline copper iridium selenide and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon alloys. The possibility of thin film multi bandgap cascade solar cells is discussed.

Landis, Geoffrey A.; Hepp, Aloysius F.

1991-01-01

338

Enhanced electrothermal pumping with thin film resistive heaters.  

PubMed

This work demonstrates the use of thin film heaters to enhance electrothermal pumping in microfluidic systems. Thin film heating electrothermal pumping is more efficient than Joule heating alone. Numerical simulations of an asymmetric electrode array are performed to demonstrate the advantages of incorporating thin film heaters. This specific simulation shows that thin film heater electrothermal pumping provides approximately two and one-half times more volumetric flow than Joule heating alone for the same input power to both systems. In addition, external heating allows for electrothermal pumping to be applicable to low conductivity media. PMID:23576002

Williams, Stuart J

2013-05-01

339

Dye-Sensitization Of Nanocrystalline ZnO Thin Films  

SciTech Connect

Nannocrystalline and nanoporus thin films of ZnO were synthesized on glass substrates by using wet chemical drop casting method. X-ray diffraction measurements on these samples confirmed the formation of ZnO nanocrystallites in hexagonal wurtzite phase with mean size of {approx}20 nm. Photo sensitization of these nanostructured ZnO thin films was carried out using three types of dyes Rhodamine 6 G, Chlorophyll and cocktail of Rhodamine 6 G and Chlorophyll in 1:1 ratio. Dye sensitized ZnO thin films showed enhanced optical absorption in visible spectral region compared to the pristine ZnO thin films.

Ajimsha, R. S.; Tyagi, M.; Das, A. K.; Misra, P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2010-12-01

340

Chemical vapor deposition of organosilicon and sacrificial polymer thin films  

E-print Network

Chemical vapor deposition (CVD) produced films for a wide array of applications from a variety of organosilicon and organic precursors. The structure and properties of thin films were controlled by varying processing ...

Casserly, Thomas Bryan

2005-01-01

341

Fluorination of amorphous thin-film materials with xenon fluoride  

DOEpatents

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

Weil, Raoul B. (Haifa, IL)

1988-01-01

342

Fluorination of amorphous thin-film materials with xenon fluoride  

DOEpatents

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

Weil, R.B.

1987-05-01

343

Flow-induced flutter of thin elastic films  

NASA Astrophysics Data System (ADS)

An experimental investigation of the aeroelastic performance of thin elastic films in flutter mode was carried out. The flow velocity of a uniform air stream was varied, as were film length, width and tension. Several commercially-available polymer films were tested. A laser vibrometer was used to acquire vibration characteristics of the film, including flutter frequency and film acceleration. Correlations between these parameters will be used to design a device to disperse particles from an adhesive film within an air stream.

Truman, C. Randall; Gallegos, Michelle; Smyth, Hugh

2007-11-01

344

Polycrystalline-thin-film thermophotovoltaic cells  

NASA Astrophysics Data System (ADS)

Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto-electronic (infrared detectors, lasers, and optical communications) technologies. Low bandgaps and larger fluences employed in TPV cells result in very high current densities which make it difficult to collect the current effectively. Techniques for laser and mechanical scribing, integral interconnection, and multi-junction tandem structures which have been fairly well developed for thin-film PV solar cells could be further refined for enhancing the voltages from TPV modules. Thin-film TPV cells may be deposited on metals or back-surface reflectors. Spectral control elements such as indium-tin oxide or tin oxide may be deposited directly on the TPV convertor. It would be possible to reduce the cost of TPV technologies based on single-crystal materials being developed at present to the range of US 2-5 per watt so as to be competitive in small to medium size commercial applications. However, a further cost reduction to the range of US ¢ 35- 1 per watt to reach the more competitive large-scale residential, consumer, and hybrid-electric car markets would be possible only with the polycrystalline-thin film TPV cells.

Dhere, Neelkanth G.

1996-02-01

345

Growth and characterisation of electrodeposited ZnO thin films  

Microsoft Academic Search

The electrochemical method has been used to deposit zinc oxide (ZnO) thin films from aqueous zinc nitrate solution at 80 °C onto fluorine doped tin oxide (FTO) coated glass substrates. ZnO thin films were grown between ? 0.900 and ? 1.025 V vs Ag\\/AgCl as established by voltammogram. Characterisation of ZnO films was carried out for both as-deposited and annealed films in order to

J. S. Wellings; N. B. Chaure; S. N. Heavens; I. M. Dharmadasa

2008-01-01

346

Amorphous silicon thin film transistor as nonvolatile device.  

E-print Network

for n+ Si film deposited at different PH3 gas phase concentration………………………………………………………... 82 1 CHAPTER I INTRODUCTION 1.1. Amorphous Silicon Thin Film Transistor (a-Si:H TFT) TFT is a type of field effect devices in which... for n+ Si film deposited at different PH3 gas phase concentration………………………………………………………... 82 1 CHAPTER I INTRODUCTION 1.1. Amorphous Silicon Thin Film Transistor (a-Si:H TFT) TFT is a type of field effect devices in which...

Nominanda, Helinda

2008-10-10

347

X-ray-induced thinning of 3 He mixture films  

E-print Network

X-ray-induced thinning of 3 He and 3 HeÃ?4 He mixture films Konstantin Penanen,* Masafumi Fukuto, Massachusetts 02138 Received 22 February 2000 Films of isotopic mixtures of helium have been studied using x in the thickness of 4 He films above the superfluid transition as well as films of pure 3 He and 3 He/4 He mixtures

Fukuto, Masafumi

348

Development of thin film solar cell based on Cu 2ZnSnS 4 thin films  

Microsoft Academic Search

Cu2ZnSnS4 (hereafter CZTS) thin films were successfully formed by vapor-phase sulfurization of precursors on a soda lime glass substrate (hereafter SLG) and a Mo-coated one (hereafter Mo-SLG). From the optical properties, we estimate the band-gap energy of this thin film as 1.45–1.6eV which is quite close to the optimum value for a solar cell. By using this thin film as

Hironori Katagiri; Kotoe Saitoh; Tsukasa Washio; Hiroyuki Shinohara; Tomomi Kurumadani; Shinsuke Miyajima

2001-01-01

349

Pulsed Laser Deposition of Epitaxial Topological Insulator Thin Films: Bi2Te3 and Bi2Te2Se  

NASA Astrophysics Data System (ADS)

While high quality epitaxial thin films of topological insulators have been achieved by molecular beam epitaxy, there has been little progress using other thin film growth techniques. Here, we report the growth of high quality epitaxial Bi2Te3 and Bi2Te2Se thin films on silicon (111) and YSZ (111) substrates by pulsed laser deposition (PLD). Systematic structural characterization of the films using x-ray diffraction and transmission electron microscopy has demonstrated that a low laser pulse rate is the key to achieving high quality epitaxial films. Rutherford backscattering spectrometry measurements suggest that the film composition is strongly influenced by the growth temperature and background gas pressure. The electrical transport properties of the films grown at the optimal conditions will also be discussed. Since PLD is an excellent tool to grow a variety of functional oxides, including multiferroics, magnetic semiconductors and high temperature superconductors, the growth of epitaxial topological insulator thin films by the same technique paves the way to synthesize multi-layered heterostructures of the above materials and search for novel physics arising from the resulting interfacial couplings.

Zhang, Shixiong; Yan, Li; Qi, Jingbo; Zhuo, Mujin; Wang, Yongqiang; Prasankumar, Rohit P.; Jia, Quanxi; Picraux, S. Tom

2012-02-01

350

Laser deposition and laser modification of high-temperature superconducting thin films  

SciTech Connect

Applications of high-temperature superconductors (HTSC) may require epitaxial films with {Tc}{ge}77 K, and J{sub c}{ge}10{sup 6} A/cm{sup 2}. In situ pulsed laser deposition (PLD) is suitable for fabrication of such films. We report parametric studies on the effect of laser and processing parameters on the crystallinity, epitaxy and electrical properties of laser-deposited HTSC thin films. In addition, several laser-based processes were used to modify the electrical properties ({Tc} and J{sub c}) of PLD thin films. A direct-write laser heating (1.06 {mu}m at {approx}0.5 kW/cm{sup 2} for {approx}5 min) process in an oxygen atmosphere at {approx}590 Torr was shown to selectivity regenerate high-{Tc} material in microscopic domains from films that were partially deoxygenated. In separate work, electrical responses and crystallinity of HTSC films were measured as a function of excimer laser exposure using fluences in the range 20--150 mJ/cm{sup 2}. The critical current and boundary layer could be modified with a high degree of accuracy. 17 refs., 4 figs.

Dye, R.C.; Foltyn, S.R.; Nogar, N.S.; Wu, X.D.; Peterson, E.J.; Muenchausen, R.E.

1991-01-01

351

Nanostructured thin films and their macrobehaviors  

NASA Astrophysics Data System (ADS)

The iridescence green band and cyan tail of the wing on Papilio blumei butterfly were investigated. The bi-color phenomenon on the scales of butterfly wings was found and analyzed. The spectral change with thickness of chitin-air layers, width of air hole, total layer numbers and incident angle of light were simulated by FDTD method. 2D photonic-crystal model was applied to explain the change of reflectance spectra and color with angle. The replica of structural color and nanostructured thin films for Papilio blumei butterflies was fabricated successfully by three main techniques, PS spheres bedding, electron-beam gun evaporation and ICP etching.

Lo, Mei-Ling; Liao, Shih-Fang; Lee, Cheng-Chung

2014-08-01

352

Mechanical behavior of mesoporous titania thin films  

NASA Astrophysics Data System (ADS)

Nanoindentation is used to assess mechanical properties of ordered mesoporous titania thin films with pore sizes in the range of 8-16 nm. Estimates of strut properties are obtained under the standard scaling assumptions widely used in porous media. The inferred hardness and fracture toughness of individual struts are found to correspond to anatase titania, indicating the absence of obvious size effects in the nanostructured ceramic. This is in marked contrast to nanoporous metals, where size effects often play a crucial role in determining material properties at similar length scales.

Rahman, Tamanna; Liu, Ran; Ortel, Erik; Kraehnert, Ralph; Antoniou, Antonia

2014-06-01

353

Articles including thin film monolayers and multilayers  

SciTech Connect

This invention pertains to thin film assemblies or devices useful as sensors, nonlinear optical materials, and trace material scavengers. It claims a base substrate having an oxide surface layer, and a multidentate ligand, capable of binding a metal ion, attached to the oxide surface layer of the base substrate. A metal species may be provided attached to the ligand, and a multifunctional organic ligand may be provided attached to the metal species. A second metal species may be provided attached to the multifunctional ligand.

Li, DeQuan; Swanson, B.I.

1992-12-31

354

Robust, Thin Optical Films for Extreme Environments  

NASA Technical Reports Server (NTRS)

The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

2006-01-01

355

Thin film photovoltaic device with multilayer substrate  

DOEpatents

A thin film photovoltaic device which utilizes at least one compound semiconductor layer chosen from Groups IIB and VA of the Periodic Table is formed on a multilayer substrate The substrate includes a lowermost support layer on which all of the other layers of the device are formed. Additionally, an uppermost carbide or silicon layer is adjacent to the semiconductor layer. Below the carbide or silicon layer is a metal layer of high conductivity and expansion coefficient equal to or slightly greater than that of the semiconductor layer.

Catalano, Anthony W. (Rushland, PA); Bhushan, Manjul (Wilmington, DE)

1984-01-01

356

Levan nanostructured thin films by MAPLE assembling.  

PubMed

Synthesis of nanostructured thin films of pure and oxidized levan exopolysaccharide by matrix-assisted pulsed laser evaporation is reported. Solutions of pure exopolysaccharides in dimethyl sulfoxide were frozen in liquid nitrogen to obtain solid cryogenic pellets that have been used as targets in pulsed laser evaporation experiments with a KrF* excimer source. The expulsed material was collected and assembled onto glass slides and Si wafers. The contact angle studies evidenced a higher hydrophilic behavior in the case of oxidized levan structures because of the presence of acidic aldehyde-hydrogen bonds of the coating formed after oxidation. The obtained films preserved the base material composition as confirmed by Fourier transform infrared spectroscopy. They were compact with high specific surface areas, as demonstrated by scanning electron and atomic force microscopy investigations. In vitro colorimetric assays revealed a high potential for cell proliferation for all coatings with certain predominance for oxidized levan. PMID:21520921

Sima, Felix; Mutlu, Esra Cansever; Eroglu, Mehmet S; Sima, Livia E; Serban, Natalia; Ristoscu, Carmen; Petrescu, Stefana M; Oner, Ebru Toksoy; Mihailescu, Ion N

2011-06-13

357

Orientation-dependent critical currents in Y sub 1 Ba sub 2 Cu sub 3 O sub 7-x epitaxial thin films: Evidence for intrinsic flux pinning  

SciTech Connect

For YBCO epitaxial thin films the basal plane transport critical current density J{sub c}, flowing perpendicular to an applied magnetic field H, depends sensitively on the orientation of the crystal with respect to H. In particular, J{sub c} is sharply peaked and greatly enhanced when H is precisely parallel to the copper-oxygen planes. Experiments on a series of epitaxial monolithic and superconductor-insulator multilayer thin films provide clear evidence that the enhancement is a bulk, rather than surface or thin sample, phenomenon. Measurements of the orientation dependence are presented and compared with a model of intrinsic flux pinning'' by the layered crystal structure.

Christen, D.K.; Klabunde, C.E.; Feenstra, R.; Lowndes, D.H.; Norton, D.P.; Budai, J.D.; Kerchner, H.R.; Thompson, J.R.; Zhu, S. (Oak Ridge National Lab., TN (USA)); Marwick, A.D. (Thomas J. Watson Research Center, Yorktown Heights, NY (USA))

1990-01-01

358

Nonlinear optical and electrical characterization of nanostructured Cu thin film  

NASA Astrophysics Data System (ADS)

Cu thin films were prepared by DC sputtering on the glass substrates. The thickness of films was in the range of 13-28 nm and the electrical and structural properties of Cu thin film as a function of thickness was evaluated. The results revealed that the grain size of the thin films was in the range of 9.2-21.3 nm. Using Z-scan method, third order optical nonlinearities of samples were measured by an excitation CW laser at the wavelength of 532 nm. The nonlinear refractive index of thin films showed a negative sign and its magnitude was in order of 10-4 cm/W. The real and imaginary parts of susceptibility were also calculated and nonlinearity dependence by thickness of thin films was investigated. The obtained results showed an increasing in nonlinear refraction with increasing thickness of samples.

Shahriari, Esmaeil; Ghasemi Varnamkhasti, Mohsen

2014-11-01

359

Thin film ferroelectric materials for microbolometer arrays  

NASA Astrophysics Data System (ADS)

This paper reviews the use of thin film ferroelectric materials for application in microbolometer infrared detector arrays. A key issue is the need for high temperature processing to achieve the required ferroelectric crystal phase. Results of thermal trials on silicon readout circuits are presented which indicate failure due to disruption of the AlCuSi metallisation. Higher temperatures can be used if oxygen is excluded. A low temperature lead zirconate titanate (PZT) sol-gel deposition is reported which has been used to fabricate fully integrated detector arrays directly on readout silicon wafers. Higher performance is obtained from dielectric bolometer materials, and materials merit figures nearly 4 times that of PZT are reported for sputtered lead scandium tantalate (PST) films. These require post-deposition annealing to temperatures above that allowable for silicon readout survival. Results on excimer laser annealing are presented which demonstrate crystallisation of a ferroelectric film without heating the underlying substrate. A new composite thermal detector array design is introduced, based on an indirect fabrication method. This uses a high density interconnect wafer as a high temperature substrate for ferroelectric film growth. After fabrication of the detector pixels, individual arrays are flip-chip bonded to readout silicon die.

Todd, Michael A.; Manning, Paul A.; Donohue, Paul P.; Brown, Alan G.; Watton, Rex

2000-12-01

360

Sputtered Thallium-Barium Superconducting Thin Films  

NASA Astrophysics Data System (ADS)

Thin films, a necessary form of materials for most sensors and electronic applications, of Tl-Ba-Ca-Cu -O have been studied. The samples were prepared by the precursor method. Precursor films of Ba-Ca-Cu-O were first deposited on the single crystal substrates of MgO, LaAlO _3, and SrTiO_3 by rf-magnetron sputtering. The following heat-treatment facilitated the incorporation of thallium into the precursor films and proper phase formation. Processing variables were systematically studied and the resulting films were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Superconducting microbridges patterned by photolithography and wet chemical etching were used for R-T and I-V characteristics measurements. The resistive broadening of superconducting transition under magnetic fields was discussed in the framework of Anderson -Kim flux-creep theory. The activation energy for the flux -creep appears to be of functional form rm U_{o}~(1-T/ rm T_{c})/B^{1/2}. .

Wu, Changyao

361

Studies on superconducting thin films for SRF applications  

SciTech Connect

In order to overcome the fundamental limit of Nb's critical magnetic field ({approx} 200 mT) that corresponds to E{sub acc} {approx}50 MV/m, an idea of coating several thin layers of a superconductor has been proposed. MgB{sub 2}, a superconductor that has a T{sub c} of {approx}39 K, has been studied to explore the effect of coating in terms of DC and RF critical magnetic fields, and RF surface losses. MgB{sub 2} has shown an excellent behavior, although there is some discrepancy between DC and RF measurements.

Tajima, Tsuyoshi [Los Alamos National Laboratory; Haberkorn, Nestor [Los Alamos National Laboratory; Civale, Leonardo [Los Alamos National Laboratory; Hawley, Marilyn [Los Alamos National Laboratory; Schulze, Roland [Los Alamos National Laboratory; Zocco, Adam [Los Alamos National Laboratory; Eremeev, Grigory [TJNAF; Guo, Jiquan [SLAC; Dolgashev, Valery [SLAC; Martin, David [SLAC; Tantawi, Sami [SLAC; Yoneda, Charles [SLAC; Doi, Toshiya [KAGOSHIMA UNIV.; Matsumoto, Akiyoshi [NIMS

2010-09-09

362

Electrodeposition and Characterization of Yttrium Barium Copper Oxide Superconducting Thin Films  

NASA Astrophysics Data System (ADS)

Precursor thin films of Y-Ba-Cu-O superconductor were produced by potentiostatic and pulse electrodeposition from the dissolved nitrate salts of Y, Ba, Cu in dimethylformamide (DMF). The films were deposited on metal foils such as Ag-coated Cu, Ag, Ni, and Zr. Films were also synthesized on Ag-coated SrTiO_3, CaTiO _3, and Al_2O _3. The electrodeposited films were heat treated in flowing O_2 in order to produce the superconducting phase. The film composition as a function of the salt concentration in DMF was determined by energy dispersive x-ray analysis. Surface compositions were obtained by Auger electron spectroscopy. Crystal structure and phases were identified by means of x-ray diffraction. The superconducting dimagnetic behaviour has been observed in magnetic measurements. Films formed by pulse plating on the titanates and on Zr exhibited the best uniformity with highest T_{rm c}. Y-Ba-Cu-O films formed on Zr had highest T_{rm c} onset at 93 K (resistance measurement). The pulse plating process was extended to the synthesis of Er-Ba-Cu-O films. On Zr, the latter resulted in a T_{rm c} onset at 80 K.

Weston, Alan James

363

Ceramics and Thick Films Based on Bi2 – x (Pb, Sb) x Sr2Ca2Cu3O y Compounds as HighT c Superconductors and Electrode Materials  

Microsoft Academic Search

Complex cuprates of the compositions Bi1.6Pb0.4Sr1.8Ca2Cu3Oy and Bi1.7Pb0.2Sb0.1Sr2Ca2Cu3Oy are synthesized. The electrical properties of the superconductors prepared are investigated. Thin films based on the bismuth cuprates studied are produced. It is demonstrated that the thin films prepared can be used as electrodes being in contact with a solid electrolyte for designing oxygen partial pressure gauges.

V. B. Glushkova; M. V. Kalinina; P. A. Tikhonov; N. S. Andreeva

2002-01-01

364

Electrodeposited CulnSe2 Thin Film Junctions  

NASA Technical Reports Server (NTRS)

We have investigated thin films and junctions based on copper indium diselenide (CIS) which have been grown by electrochemical deposition. CIS is a leading candidate for use in polycrystalline thin film photovoltaic solar cells. Electrodeposition is a cost-effective method for producing thin-film CIS. We have produced both p and n type CIS thin films from the same aqueous solution by simply varying the deposition potential. A CIS pn junction was deposited using a step-function potential. Stoichiometry of the single layer films was determined by energy dispersive spectroscopy. Carrier densities of these films increased with deviation from stoichiometry, as determined by the capacitance versus voltage dependence of Schottky contacts. Optical bandgaps for the single layer films as determined by transmission spectroscopy were also found to increase with deviation from stoichiometry. Rectifying current versus voltage characteristics were demonstrated for the Schottky barriers and for the pn junction.

Raffaelle, R. P.; Mantovani, J. G.; Bailey, S. G.; Hepp, A. F.; Gordon, E. M.; Haraway, R.

1998-01-01

365

Electrodeposited CuInSe2 Thin Film Junctions  

NASA Technical Reports Server (NTRS)

We have investigated thin films and junctions based on copper indium diselenide (CIS) which have been grown by electrochemical deposition. CIS is a leading candidate for use in polycrystalline thin film photovoltaic solar cells. Electrodeposition is a cost-effective method for producing thin-film CIS. We have produced both p and n type CIS thin films from the same aqueous solution by simply varying the deposition potential. A CIS pn junction was deposited using a step-function potential. Stoichiometry of the single layer films was determined by energy dispersive spectroscopy. Carrier densities of these films increased with deviation from stoichiometry, as determined by the capacitance versus voltage dependence of Schottky contacts. Optical bandgaps for the single layer films as determined by transmission spectroscopy were also found to increase with deviation from stoichiometry. Rectifying current versus voltage characteristics were demonstrated for the Schottky barriers and for the pn junction.

Raffaelle, R. P.; Mantovani, J. G.; Bailey, S. G.; Hepp, A. F.; Gordon, E. M.; Haraway, R.

1997-01-01

366

The role of microstructural phenomena in magnetic thin films  

SciTech Connect

The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

Laughlin, D.E.; Lambeth, D.N.

1992-01-01

367

The role of microstructural phenomena in magnetic thin films  

SciTech Connect

The subject is germane to magnetic recording media. Results during the first 2 years are presented under the following headings: atomic resolution TEM of CoNiCr films; CoNiCr and CoCrTa thin films; development of texture; and CoSm/Cr thin films. The HREM results showed that defects in Co-based films may be responsible for higher coercivity. Findings are presented on the effects of Cr interlayers on the microstructure of the second Co-based film in Co/Cr/Co/Cr multilayer films. Proposed research plans are outlined.

Laughlin, D.E.; Lambeth, D.N.

1992-12-31

368

thin films toward less leakage currents  

NASA Astrophysics Data System (ADS)

To prepare high-density integrated capacitors with low leakage currents, 0.2-?m-thick BaTiO3 thin films were successfully deposited on integrated semiconductor substrates at room temperature by the aerosol deposition (AD) method. In this study, the effects of starting powder size were considered in an effort to remove macroscopic defects. A surface morphology of 25.3 nm and an interface roughness of less than 50 nm were obtained using BT-03B starting powder. The nano-crystalline thin films achieved after deposition were annealed at various temperatures to promote crystallization and densification. Moreover, the influence of rapid thermal annealing process on the surface morphology and crystal growth was evaluated. As the annealing temperature increased from room temperature to 650°C, the root mean square (RMS) roughness decreased from 25.3 to 14.3 nm. However, the surface was transformed into rough performance at 750°C, which agreed well with the surface microstructure trend. Moreover, the crystal growth also reveals the changes in surface morphology via surface energy analysis.

Yao, Zhao; Wang, Cong; Li, Yang; Kim, Hong-Ki; Kim, Nam-Young

2014-08-01

369

Apparatus for laser assisted thin film deposition  

DOEpatents

A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus.

Warner, Bruce E. (Pleasanton, CA); McLean, II, William (Oakland, CA)

1996-01-01

370

Apparatus for laser assisted thin film deposition  

DOEpatents

A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus. 9 figs.

Warner, B.E.; McLean, W. II

1996-02-13

371

Surface Properties of Bottlebrush Copolymer Thin Films  

NASA Astrophysics Data System (ADS)

Bottlebrush polymers are novel macromolecules with polymeric side-chains. Due to their large size and densely crowded side-chains, bottlebrush polymers are candidates for a number of potential applications, including rheological modifiers, drug-delivery vehicles, and polymeric photonics. However, the structural details of bottlebrush polymers in solution and in the bulk are poorly understood. For example, while the overall size of bottlebrush polymers has been measured, the polymer stiffness and side-chain conformation have not been quantified. Here, we present a study of the surface properties of well-defined bottlebrush polymer and copolymer thin films. Surface property measurements provide a method to investigate polymeric side-chain conformation and flexibility. Bottlebrush polymers with mixed and copolymer side-chains are prepared via living ring-opening metathesis polymerization of norbornene-functionalized macromonomers. Contact angle measurements, x-ray photoelectron spectroscopy, and atomic force microscopy measurements on bottlebrush polymer thin films show that polymeric side-chains have significant conformational flexibility and that bottlebrush polymers with mixed and copolymer side-chains can be used to prepare stimuli-responsive surfaces.

Li, Xianyu; Prukop, Stacy; Verduzco, Rafael

2012-02-01

372

Characterization of optical thin films exhibiting defects  

NASA Astrophysics Data System (ADS)

In this paper the mathematical formalism enabling us to include defects of thin films into the formulae expressing their optical quantities is presented. The attention is devoted to the defects consisting in boundary roughness and inhomogeneity corresponding to the refractive index profile. This mathematical formalism is based on 2x2 matrix algebra. The Rayleigh-Rice theory (RRT) is used for describing boundary roughness. The refractive index profile is included into the matrix formalism by means a special procedure based on combination of the Drude and Wentzel-Kramers-Brillouin-Jeffries (WKBJ) approximations. The mathematical formalism is applied for the optical characterization of thin films of TiO2 and As-S chalcogenides. Using this formalism the experimental data corresponding to the ellipsometric quantities, reflectance measured from the ambient side, reflectance measured from the substrate side and transmittance are treated. The corrections of the systematic errors connected with the reflection accessory of the spectrometer used is carried out using the special procedure.

Franta, Daniel; Ohlídal, Ivan

2005-09-01

373

Thinning and rupture of a thin liquid film on a heated surface  

SciTech Connect

Results on the dynamics and stability of thin films are summarized on the following topics: forced dryout, film instabilities on a horizontal plane and on inclined planes, instrumentation, coating flows, and droplet spreading. (DLC)

Bankoff, S.G.; Davis, S.H.

1992-08-05

374

Electrochemical studies of substituted spinel thin films  

SciTech Connect

Thin lithium manganese oxide spinel films, prepared with pulsed laser deposition have been used as a model system for the study of oxide electrochemical properties and performance degradation mechanisms in the absence of carbon or binder materials. Films (0.3 {micro}m) of Li{sub x}Mn{sub 2{minus}y}Me{sub y}O{sub 4}, where Me = Ni, Co and y = 0, 0.1, 0.25, were crystalline as-prepared. The cyclic voltammetric response as a function of oxide composition was measured in liquid electrolyte over the range of 2 to 5.8 V vs. Li/Li{sup +}. Quantitative analysis of the two 4 V peaks, for x > 0.5 and x < 0.5, correlated well with predicted film stoichiometry. The capacity of the 4.6 V redox peaks in the Ni-substituted films were consistent with the oxidation of Ni{sup 2+} to Ni{sup 4+}. No significant capacity was observed in LiMn{sub 2}O{sub 4} above 4.5 V. The shape of the voltammetric peaks in the 3 V region suggested that intercalation kinetics are slowed by the Jahn-Teller distortion, while all compositions in the 4 V region showed reversible behavior, except for the LiNi{sub 0.25}Mn{sub 1.75}O{sub 4} film which showed lower electronic conductivity. The LiMn{sub 1.90}Ni{sub 0.10}O{sub 4} films showed no loss in discharge capacity after being charged up to 5.7 V vs. Li/Li{sup +} with window-opening cyclic voltammetry. LiMn{sub 2}O{sub 4} and LiMn{sub 1.75}Co{sub 0.25}O{sub 4} films were stable to 5.6 and 5.4 V vs. Li/Li{sup +}, respectively. Explanations for the superior stability of the films relative to powder electrodes are examined.

Striebel, K.A.; Rougier, A.; Horne, C.R.; Reade, R.P.; Cairns, E.J.

1999-12-01

375

Critical Currents and Flux Creep in Yttrium BARIUM(2) COPPER(3) OXIDE(7-DELTA) Superconducting Thin Films  

NASA Astrophysics Data System (ADS)

Transport critical currents are not a fundamental property of superconductors. Rather, critical currents in superconducting materials are determined by a variety of considerations, including fundamental thermodynamic properties and the microstructure of the material. The motivation for the present work is both technological, since high transport critical currents are essential for many applications, and fundamental. We investigate the effect of changing various parameters in the film growth recipe, with the goal of being able to make known changes in the structure of in-situ grown films. The basic features of synthesis, critical currents, and flux creep in typical films are measured and characterized. Systematic changes in the microstructure of the films are made, which are then related, in some instances, to observed critical currents and flux creep. A serious difficulty with establishing relationships of this sort is that vortex interactions with the high T_{c} materials and the mechanisms for pinning are not well understood. As a partial remedy, the analysis of flux pinning potentials is developed to a level of sophistication which is suitable for application to high temperature superconductors. The applicability of this analysis to high T_ {c} superconducting thin films is investigated, and the model is then applied to the study of oxygen deficient YBa_2Cu _3O_{7-delta} thin films.

Lairson, Bruce Michael

376

Preparation of transparent conductive AZO thin films for solar cells  

Microsoft Academic Search

A study of the effect of technology parameters (sputtering power, substrate temperature and post-deposition annealing) on structural, electrical and optical properties of aluminium-doped zinc oxide (AZO) thin films was carried out. The optimal technology parameters of preparation were found to get necessary properties of AZO thin films for application in solar cells - the high figure of merit (F ges

V. Tvarozek; P. Sutta; I. Novotny; P. Ballo; L. Harmatha; S. Flickyngerova; L. Prusakova; M. Netrvalova; V. Vavrunkova; A. Pullmannova; E. Vavrinsky; P. Gaspierik; M. Mikolasek

2008-01-01

377

Single walled carbon nanotube thin films: Properties and applications  

Microsoft Academic Search

The work presented in this thesis discusses the synthesis, purification, dispersion, characterization and deposition of single walled carbon nanotubes (SWNTs). Specifically, the deposition of SWNT thin films, their optoelectronic properties, and applications in organic photovoltaic devices and thin film transistors (TFTs) is reported. The motivation for this work has been to understand the opto-electronic properties of SWNTs in order to

Husnu Emrah Unalan

2006-01-01

378

Tools to Synthesize the Learning of Thin Films  

ERIC Educational Resources Information Center

After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase…

Rojas, Roberto; Fuster, Gonzalo; Slusarenko, Viktor

2011-01-01

379

Polymer assisted deposition of electrochromic tungsten oxide thin films  

Microsoft Academic Search

We report the synthesis of structurally and uniformly deposited porous tungsten oxide (WO3) thin films for the first time by the novel route of polymer assisted deposition (PAD) using ammonium tungstate as a precursor with polyvinyl alcohol (PVA) as an additive. The effect of deposition parameters on the morphological, optical and electrochemical performance of the thin films is investigated. WO3

S. S. Kalagi; D. S. Dalavi; R. C. Pawar; N. L. Tarwal; S. S. Mali; P. S. Patil

2010-01-01

380

APPLIED PHYSICS REVIEWS Erbium implanted thin film photonic materials  

E-print Network

, phosphosilicate, borosilicate, and soda-lime glasses , ceramic thin films Al2O3, Y2O3, LiNbO3 , and amorphous Er-doped thin film photonic materials is described. It focuses on oxide glasses pure SiO2 characterization. . . . . . . . . . . . . . . . . . . . 4 III. Silica Glasses

Polman, Albert

381

Wave propagation in highly inhomogeneous thin films: exactly solvable models  

E-print Network

. The first analytical results were obtained by Rayleigh for waves whose velocity inside the medium dependsWave propagation in highly inhomogeneous thin films: exactly solvable models Guillaume Petite(1 of wave propagation in some inhomogeneous thin films with highly space- dependent dielectric constant

Boyer, Edmond

382

Atomic hydrogen desorption from thin palladium hydride films  

NASA Astrophysics Data System (ADS)

It has been proved that hydrogen atoms desorb from the surface of a decomposing thin palladium hydride film. A thin gold film deposited and sintered in situ was used as a selective adsorbent for atomic hydrogen. The TDMS (thermal desorption mass spectrometry) technique was applied to detect the adsorption of hydrogen on gold and to determine the amount adsorbed.

Lisowski, W.; Nowicka, E.; Wolfram, Z.; Du?, R.

1988-01-01

383

Instabilities in Gravity Driven Flow of Thin Fluid Films  

Microsoft Academic Search

This paper presents theoretical, computational, and experimental aspects of the instability development in the flow of thin fluid films. The theoretical part involves basic fluid me- chanics and presents derivation of the thin film equation using lubrication approximation. A simplified version of this equation is then analyzed analytically using linear stability analysis, and also numerically. The results are then compared

L. Kondic

2003-01-01

384

Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films  

E-print Network

Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films A dissertation presented Advisor Author Joost J. Vlassak Patrick J. McCluskey Thermal Sensor Arrays for The Combinatorial Analysis of Thin Films Abstract Membrane-based thermal sensor arrays were developed for the high- throughput

385

A survey of thin-film solar photovoltaic industry & technologies  

E-print Network

A new type of solar cell technology using so-called thin-film solar photovoltaic material has the potential to make a great impact on our lives. Because it uses very little or no silicon at all, thin- film (TF) solar ...

Grama, Sorin

2007-01-01

386

Measurement of yield strength of thin metal film  

Microsoft Academic Search

Based on measurement of the load-depth curve in nanoindentation, the yield strength of thin metal film on Si substrate can be determined with the model of finite element analysis. An example is given of thin Cu film and the result shows that the yield strength thus determined can eventually reflect changes of processing condition both in deposition and in post-treatment.

Fei Wang; Kewei Xu

2004-01-01

387

XPS depth profile study of sprayed CZTS thin films  

NASA Astrophysics Data System (ADS)

XPS depth profile studies were carried out to analyze the composition and stoichiometry of sprayed CZTS thin films giving an efficiency of 1.85% in CZTS based thin film solar cell. Surface layers were nearly stoichiometric (Cu:Zn:Sn:S=2:1:1:4) whereas the inner layers were found to be Copper rich in composition making it electrically more conductive.

Deepu, D. R.; Rajeshmon, V. G.; Kartha, C. Sudha; Vijayakumar, K. P.

2014-04-01

388

Applications of Thin Film Thermocouples for Surface Temperature Measurement  

NASA Technical Reports Server (NTRS)

Thin film thermocouples provide a minimally intrusive means of measuring surface temperature in hostile, high temperature environments. Unlike wire thermocouples, thin films do not necessitate any machining of the surface, therefore leaving intact its structural integrity. Thin films are many orders of magnitude thinner than wire, resulting in less disruption to the gas flow and thermal patterns that exist in the operating environment. Thin film thermocouples have been developed for surface temperature measurement on a variety of engine materials. The sensors are fabricated in the NASA Lewis Research Center's Thin Film Sensor Lab, which is a class 1000 clean room. The thermocouples are platinum-13 percent rhodium versus platinum and are fabricated by the sputtering process. Thin film-to-leadwire connections are made using the parallel-gap welding process. Thermocouples have been developed for use on superalloys, ceramics and ceramic composites, and intermetallics. Some applications of thin film thermocouples are: temperature measurement of space shuttle main engine turbine blade materials, temperature measurement in gas turbine engine testing of advanced materials, and temperature and heat flux measurements in a diesel engine. Fabrication of thin film thermocouples is described. Sensor durability, drift rate, and maximum temperature capabilities are addressed.

Martin, Lisa C.; Holanda, Raymond

1994-01-01

389

Ferroelectric thin films: Review of materials, properties, and applications  

Microsoft Academic Search

An overview of the state of art in ferroelectric thin films is presented. First, we review applications: microsystems' applications, applications in high frequency electronics, and memories based on ferroelectric materials. The second section deals with materials, structure (domains, in particular), and size effects. Properties of thin films that are important for applications are then addressed: polarization reversal and properties related

N. Setter; D. Damjanovic; L. Eng; G. Fox; S. Gevorgian; S. Hong; A. Kingon; H. Kohlstedt; N. Y. Park; G. B. Stephenson; I. Stolitchnov; A. K. Taganstev; D. V. Taylor; T. Yamada; S. Streiffer

2006-01-01

390

Thermal transition measurements of polymer thin films by modulated nanoindentation  

E-print Network

Thermal transition measurements of polymer thin films by modulated nanoindentation Scott Sills nanoindentation technique has been developed for thermal transition analysis of polymer thin films. The procedure and depth-sensing nanoindentation.6 In- terest in these techniques has been motivated by the attain- able

391

Determination of optical constant of diamond thin films  

Microsoft Academic Search

Refractive index N, extinction coefficient k, and surface roughness (alpha) of synthetic diamond thin films are strongly dependent on the growth process. The current presentation describes a multiparameter optical transmittance curve fitting method to determine refractive index n, extinction coefficient k, thickness t, and surface roughness (alpha) of synthetic CVD diamond thin films taking account optical scattering of the light

Xuantong Ying; Yuan-Hua Shen; Hang Xue; Jianhai Liu; Zhongjing Xing; Jianzhong Xu; Fen-Shan Zhang

1992-01-01

392

Efficient light trapping structure in thin film silicon solar cells  

Microsoft Academic Search

Thin film silicon solar cells are believed to be promising candidates for continuing cost reduction in photovoltaic panels because silicon usage could be greatly reduced. Since silicon is an indirect bandgap semiconductor, its absorption coefficient is low for photons in the wavelength ranges between 600nm and 1100nm. For high efficiency thin film modules, effective light trapping is essential. Traditional schemes

Xing Sheng; Jifeng Liu; I. Kozinsky; A. M. Agarwal; J. Michel; L. C. Kimerling

2010-01-01

393

Electrochemical photovoltaic cells 2-6 compound thin film electrodes  

Microsoft Academic Search

The program focused on developing stable, thin film II-VI compound electrodes with sunlight efficiencies of 10%, for use with aqueous polysulfide electrolyte in frontwall and backwall illuminated electrochemical photovoltaic cells. The main effort was directed towards establishing the relationships among processing of the thin films, resultant electronic properties, and I-V performance in order to produce electrodes with maximum power conversion

M. A. Russak; J. Reichman; J. Decarlo; C. Creter

1981-01-01

394

Thin film knitting pattern morphology from a miktoarm star terpolymer.  

PubMed

Thin film knitting pattern from a miktoarm star terpolymer is demonstrated. Such structures have been predicted but not observed in bulk or thin film form. The knitting pattern exhibits well organized periodic structures consisting of undulating lamellae and alternating cylinders, with well-defined defects that result in sharp 90° bends and T junctions. PMID:24469920

Choi, Hong Kyoon; Nunns, Adam; Sun, Xue Yin; Manners, Ian; Ross, Caroline A

2014-04-23

395

Thin film Bragg lasers and waveguides by liquid phase epitaxy  

Microsoft Academic Search

The theory and device applications of periodically corrugated thin film waveguides are described. Specifically, the main concern is their use as Bragg reflectors and grating output couplers in GaAs semiconductor lasers. The theory of periodic thin film waveguides is well described by the coupled mode formalism. Experimental work with optically pumped and heterojunction GaAs distributed Bragg reflector lasers operating with

W. W. L. Ng

1979-01-01

396

NbN thin films for superconducting radio frequency cavities  

NASA Astrophysics Data System (ADS)

NbN thin films have the potential to be incorporated into radio frequency cavities in a multilayer coating to overcome the fundamental field gradient limit of 50 MV m-1 for the bulk niobium based technology that is currently implemented in particle accelerators. In addition to having a larger critical field value than bulk niobium, NbN films develop smoother surfaces which are optimal for cavity performance and lead to fewer losses. Here, we present a study on the correlation of film deposition parameters, surface morphology, microstructure, transport properties and superconducting properties of NbN thin films. We have achieved films with bulk-like lattice parameters and superconducting transition temperatures. These NbN films have a lower surface roughness than similarly grown niobium films of comparable thickness. The potential application of NbN thin films in accelerator cavities is discussed.

Roach, W. M.; Skuza, J. R.; Beringer, D. B.; Li, Z.; Clavero, C.; Lukaszew, R. A.

2012-12-01

397

Buckling thin films with inhomogeneous swelling  

NASA Astrophysics Data System (ADS)

The shapes of many leaves and flowers are determined, at least in part, by their inhomogeneous growth. Additional growth at the edges of leaves, for example, result in saddle-splay curvature and, ultimately, wrinkling. Recent experiments on thin, polymer films imprinted with a predefined pattern of inhomogeneous swelling provide a controlled, experimental playground for describing how swelling-induced buckling leads to a prescribed three-dimensional shape. For example, one expects a sufficiently thin sheet to buckle into a shape that eliminates most of its in-plane strain. Though this is always possible locally, a particular swelling pattern may be either globally frustrated, having no stress-free shapes even for vanishing thickness, or lead to a large degeneracy of stress-free shapes. In both cases, the bending energy remains important even for very thin sheets. I will describe theoretical work on disks and narrow ribbons with swelling-induced, negative Gaussian curvature. Perhaps surprisingly, when the prescribed Gaussian curvature is constant, there are families of stress-free and nearly stress-free shapes, none of which seem to appear in experiments. To understand this behavior, I will identify regimes in which the minimal energy ribbon shape can be determined and discuss the role of stretching and bending energies. We will consider both strips and closed ribbons.

Santangelo, Christian

2010-03-01

398

Thickness dependence of conduction currents in ultra thin evaporated polypropylene films  

Microsoft Academic Search

A ultra thin polypropylene film (thin PP film) was deposited on a glass substrate by the vacuum evaporation method. A thin PP film deposited on a glass substrate at room temperature was annealed for one hour in N2. Thin PP films are about 60~1.50 A in thickness. Aluminum electrodes (2 mm square) were evaporated on both sides of a thin

S. Ochiai; T. Kato; T. Ogawa; K. Kojima; Y. Uchida; A. Ohashi; M. Ieda; T. Mizutani

1994-01-01

399

Information-bearing structures and magnetism of thin films. Annual report, 1997--1998  

SciTech Connect

Progress is reported on the following: theory of Skyrmions in magnetic films; hystersis in thin magnetic films; interaction of magnetic dots with superconducting films;and phase transformations in thin magnetic films.

Pokrovsky, V.L.; Saslow, W.M.

1998-06-01

400

Pulsed Laser Deposition of Nanoporous Cobalt Thin Films  

PubMed Central

Nanoporous cobalt thin films were deposited on anodized aluminum oxide (AAO) membranes at room temperature using pulsed laser deposition. Scanning electron microscopy demonstrated that the nanoporous cobalt thin films retained the monodisperse pore size and high porosity of the anodized aluminum oxide substrates. Temperature- and field-dependent magnetic data obtained between 10 K and 350 K showed large hysteresis behavior in these materials. The increase of coercivity values was larger for nanoporous cobalt thin films than for multilayered cobalt/alumina thin films. The average diameter of the cobalt nanograins in the nanoporous cobalt thin films was estimated to be ~5 nm for blocking temperatures near room temperature. These results suggest that pulsed laser deposition may be used to fabricate nanoporous magnetic materials with unusual properties for biosensing, drug delivery, data storage, and other technological applications. PMID:19198344

Jin, Chunming; Nori, Sudhakar; Wei, Wei; Aggarwal, Ravi; Kumar, Dhananjay; Narayan, Roger J.

2013-01-01

401

Tailoring Thin Film-Lacquer Coatings for Space Application  

NASA Technical Reports Server (NTRS)

Thin film coatings have the capability of obtaining a wide range of thermal radiative properties, but the development of thin film coatings can sometimes be difficult and costly when trying to achieve highly specular surfaces. Given any space mission's thermal control requirements, there is often a need for a variation of solar absorptance (Alpha(s)), emittance (epsilon) and/or highly specular surfaces. The utilization of thin film coatings is one process of choice for meeting challenging thermal control requirements because of its ability to provide a wide variety of Alpha(s)/epsilon ratios. Thin film coatings' radiative properties can be tailored to meet specific thermal control requirements through the use of different metals and the variation of dielectric layer thickness. Surface coatings can be spectrally selective to enhance radiative coupling and decoupling. The application of lacquer to a surface can also provide suitable specularity for thin film application without the cost and difficulty associated with polishing.

Peters, Wanda C.; Harris, George; Miller, Grace; Petro, John

1998-01-01

402

Development of a thin film solid state gaseous HCl sensor  

NASA Technical Reports Server (NTRS)

The selection of materials to develop a thin film HCl sensor is discussed. Data were primarily concerned with chemical and physical properties of the film and with electrical properties which exhibit and enhance electrical response when HCl is absorbed on the film surface. Techniques investigated for enhancing electrical response include changing conditions for growing films, adding impurities to the film, changing ambient light intensity, and altering the ambient temperature of the sensing element.

1975-01-01

403

A Chemical Method for Preparing Copper Iodide Thin Films  

NASA Astrophysics Data System (ADS)

A chemical method for preparing CuI thin films by iodination of solution grown Cu2S films is described. X-ray characterization identifies ?-CuI and suggest that the films are polycrystalline in nature. SEM reveals a granular film morphology. Optical studies show that the band gap of the material is 2.93 eV. The sheet resistance of the films is in the range 1 to 3 k?/sq.

Chaudhuri, T. K.; Basu, P. K.; Patra, A. B.; Saraswat, R. S.; Acharya, H. N.

1990-02-01

404

Controlled nanostructuration of polycrystalline tungsten thin films  

SciTech Connect

Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l'Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d'Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

2013-05-07

405

Interfacial Dynamics in Thin Perfluorinated Ionomer Films  

NASA Astrophysics Data System (ADS)

Continued interest in fluoroionomers for applications ranging from coatings to proton exchange membranes (PEM) in fuel cells has motivated the study of their interfacial dynamics by Atomic Force Microscopy (AFM). A stable interface is a key component in the performance of fluoroionomers in these applications. Fluoroionomers contain a rigid fluorinated hydrophobic backbone and short hydrophilic side chains, with which a counter ion is associated. The wetting behavior of spin cast films was studied using tapping mode AFM as a function of annealing time (T > Tg) and driving amplitude, A0 and set point amplitude ratio, rsp = Asp/A0, where Asp is the set-point amplitude. We have shown thin spin cast films on the order of 1750 ± 270 Å do not de-wet via spinodal decomposition nor nucleation and growth of holes. From 2D Fourier transform of the images, a preferred orientation is observed in the one direction prior to annealing, indexing on hexagonal lattice. Upon annealing, reorientation occurs, possibly moving towards lamellar packing. Annealing and concentration effects were also studied in self-assembled films.

Hill, Teresa A.; Perahia, Dvora

2001-03-01

406

Vertically aligned biaxially textured molybdenum thin films  

NASA Astrophysics Data System (ADS)

Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85° with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85° without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

Krishnan, Rahul; Riley, Michael; Lee, Sabrina; Lu, Toh-Ming

2011-09-01

407

Pressureless Bonding Using Sputtered Ag Thin Films  

NASA Astrophysics Data System (ADS)

To improve the performance and reliability of power electronic devices, particularly those built around next-generation wide-bandgap semiconductors such as SiC and GaN, the bonding method used for packaging must change from soldering to solderless technology. Because traditional solders are problematic in the harsh operating conditions expected for emerging high-temperature power devices, we propose a new bonding method in this paper, namely a pressureless, low-temperature bonding process in air, using abnormal grain growth on sputtered Ag thin films to realize extremely high temperature resistance. To investigate the mechanisms of this bonding process, we characterized the microstructural changes in the Ag films over various bonding temperatures and times. We measured the bonding properties of the specimens by a die-shear strength test, as well as by x-ray diffraction measurements of the residual stress in the Ag films to show how the microstructural developments were essential to the bonding technology. Sound bonds with high die strength can be achieved only with abnormal grain growth at optimum bonding temperature and time. Pressureless bonding allows for production of reliable high-temperature power devices for a wide variety of industrial, energy, and environmental applications.

Oh, Chulmin; Nagao, Shijo; Suganuma, Katsuaki

2014-08-01

408

Oxynitride Thin Film Barriers for PV Packaging  

SciTech Connect

Dielectric thin-film barrier and adhesion-promoting layers consisting of silicon oxynitride materials (SiOxNy, with various stoichiometry) were investigated. For process development, films were applied to glass (TCO, conductive SnO2:F; or soda-lime), polymer (PET, polyethylene terephthalate), aluminized soda-lime glass, or PV cell (a-Si, CIGS) substrates. Design strategy employed de-minimus hazard criteria to facilitate industrial adoption and reduce implementation costs for PV manufacturers or suppliers. A restricted process window was explored using dilute compressed gases (3% silane, 14% nitrous oxide, 23% oxygen) in nitrogen (or former mixtures, and 11.45% oxygen mix in helium and/or 99.999% helium dilution) with a worst-case flammable and non-corrosive hazard classification. Method employed low radio frequency (RF) power, less than or equal to 3 milliwatts per cm2, and low substrate temperatures, less than or equal to 100 deg C, over deposition areas less than or equal to 1000 cm2. Select material properties for barrier film thickness (profilometer), composition (XPS/FTIR), optical (refractive index, %T and %R), mechanical peel strength and WVTR barrier performance are presented.

Glick, S. H.; delCueto, J. A.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M.; Gedvilas, L. M.; Pern, F. J.

2005-11-01

409

Method of producing solution-derived metal oxide thin films  

DOEpatents

A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

Boyle, Timothy J. (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

2000-01-01

410

STRESS-INDUCED PERIODIC FRACTURE PATTERNS IN THIN FILMS Alex A. Volinsky1  

E-print Network

STRESS-INDUCED PERIODIC FRACTURE PATTERNS IN THIN FILMS Alex A. Volinsky1 , Neville R. Moody2 applied stresses in thin films can cause film fracture. In the case of compressive stress thin film stress a network of through- thickness cracks forms in thin films. Excessive biaxial residual stress

Volinsky, Alex A.

411

Solution Processed Graphene for Utilization in Thin Films  

NASA Astrophysics Data System (ADS)

Solution processing of graphene offers a method for increasing the purity and uniformity of the deposited thin films. Solubility parameters are useful in preparing dispersions and have been employed successfully with CNTs. Applying solubility parameters and solution processing techniques to graphene provides an avenue for both higher purity samples and more uniform thin films. The various families of solvents have different solubility parameters and careful selection of these parameters will help the quality of dispersions. Vacuum filtration and density centrifugation allow for filtering of the material, while annealing films is known to fix defects and improve structure. Through filtration, film deposition, and thermal annealing, graphene thin films of higher purity and uniformity will lead to graphene thin films that have the theoretical properties closer to ideal single crystal graphene. These properties have major applications in the fields of solar power and organic light emitting diodes as transparent electrodes and electron donor material.

Belew, Jonathan

2012-10-01

412

Template engineering of Co-doped BaFe2As2 single-crystal thin films.  

PubMed

Understanding new superconductors requires high-quality epitaxial thin films to explore intrinsic electromagnetic properties and evaluate device applications. So far, superconducting properties of ferropnictide thin films seem compromised by imperfect epitaxial growth and poor connectivity of the superconducting phase. Here we report new template engineering using single-crystal intermediate layers of (001) SrTiO(3) and BaTiO(3) grown on various perovskite substrates that enables genuine epitaxial films of Co-doped BaFe(2)As(2) with a high transition temperature (T(c,rho=0) of 21.5 K, where rho=resistivity), a small transition width (DeltaT(c)=1.3 K), a superior critical current density J(c) of 4.5 MA cm(-2) (4.2 K) and strong c-axis flux pinning. Implementing SrTiO(3) or BaTiO(3) templates to match the alkaline-earth layer in the Ba-122 with the alkaline-earth/oxygen layer in the templates opens new avenues for epitaxial growth of ferropnictides on multifunctional single-crystal substrates. Beyond superconductors, it provides a framework for growing heteroepitaxial intermetallic compounds on various substrates by matching interfacial layers between templates and thin-film overlayers. PMID:20190768

Lee, S; Jiang, J; Zhang, Y; Bark, C W; Weiss, J D; Tarantini, C; Nelson, C T; Jang, H W; Folkman, C M; Baek, S H; Polyanskii, A; Abraimov, D; Yamamoto, A; Park, J W; Pan, X Q; Hellstrom, E E; Larbalestier, D C; Eom, C B

2010-05-01

413

Characterization of reliability of printed indium tin oxide thin films.  

PubMed

Recently, decreasing the amount of indium (In) element in the indium tin oxide (ITO) used for transparent conductive oxide (TCO) thin film has become necessary for cost reduction. One possible approach to this problem is using printed ITO thin film instead of sputtered. Previous studies showed potential for printed ITO thin films as the TCO layer. However, nothing has been reported on the reliability of printed ITO thin films. Therefore, in this study, the reliability of printed ITO thin films was characterized. ITO nanoparticle ink was fabricated and printed onto a glass substrate followed by heating at 400 degrees C. After measurement of the initial values of sheet resistance and optical transmittance of the printed ITO thin films, their reliabilities were characterized with an isothermal-isohumidity test for 500 hours at 85 degrees C and 85% RH, a thermal shock test for 1,000 cycles between 125 degrees C and -40 degrees C, and a high temperature storage test for 500 hours at 125 degrees C. The same properties were investigated after the tests. Printed ITO thin films showed stable properties despite extremely thermal and humid conditions. Sheet resistances of the printed ITO thin films changed slightly from 435 omega/square to 735 omega/square 507 omega/square and 442 omega/square after the tests, respectively. Optical transmittances of the printed ITO thin films were slightly changed from 84.74% to 81.86%, 88.03% and 88.26% after the tests, respectively. These test results suggest the stability of printed ITO thin film despite extreme environments. PMID:24245331

Hong, Sung-Jei; Kim, Jong-Woong; Jung, Seung-Boo

2013-11-01

414

Tensile and Adhesion Properties of Metal Thin Films Deposited onto Polyester Film Substrate Prepared by a Conventional Vacuum Evaporator  

NASA Astrophysics Data System (ADS)

Four kinds of metal, such as aluminum, copper, indium and tin, thin films were deposited onto polyester (PET) substrate by a conventional vacuum evaporator and evaluated their tensile and adhesion properties. The tensile property was estimated by observations of micro-cracks of the thin films due to the tensile test at 150°C. The tensile property of the metal thin films seems to relate with Brinell hardness and thickness of the thin film. The adhesion property of these metal thin films was estimated by measuring the pull strength. Aluminum thin film showed highest pull strength of all the thin films, and the pull strength increased with increase of the thickness.

Kita, Takuya; Saitoh, Shou; Iwamori, Satoru

415

Photon down-conversion in Terbium(III)-doped thin dielectric films and fluorozirconate glasses for thin film solar cells  

Microsoft Academic Search

The efficiency of thin film solar cells can be improved with the addition of a photon down-conversion top layer. This layer converts incident ultraviolet light of the solar spectrum to visible light, which transmits through the glass and is efficiently absorbed by the active layer of the solar cell. The results of our investigations of thin dielectric films and fluorozirconate

K. Baumgartner; B. Ahrens; O. Angelov; M. Sendova-Vassileva; D. Dimova-Malinovska; B. Holländer; S. Schweizer; R. Carius

2010-01-01

416

4E-6 Electric Field Sensitivity of Thin Film Resonators Based on Piezoelectric AlN Thin Films  

Microsoft Academic Search

Thin film bulk acoustic wave resonators (FBAR), solidly mounted resonators (SMR), and thin film plate acoustic resonators (FPAR) based on piezoelectric aluminum nitride (AlN) are all attractive candidates for monolithically integrated filters, sensors and oscillators operating in the gigahertz frequency range. This work aims at performing a systematic study of the DC electric field sensitivity of FBAR, SMR and FPAR

J. Enlund; V. Yantchev; I. Katardjiev

2006-01-01

417

Surface textured molybdenum doped zinc oxide thin films prepared for thin film solar cells using pulsed direct current magnetron sputtering  

Microsoft Academic Search

In this study, we examined the effect of etching on the electrical properties, transmittance, and scattering of visible light in molybdenum doped zinc oxide, ZnO:Mo (MZO) thin films prepared by pulsed direct current magnetron sputtering. We used two different etching solutions – KOH and HCl – to alter the surface texture of the MZO thin film so that it could

Y. C. Lin; B. L. Wang; W. T. Yen; C. H. Shen

2011-01-01

418

Interconnected Si nanocrystals forming thin films with controlled bandgap values  

SciTech Connect

Interconnected Si nanocrystals forming homogeneous thin films with controlled bandgap values from 1.2 to 2.9 eV were formed by pulsed plasma enhanced chemical vapor deposition technique under dusty plasma conditions. The chosen values of plasma duration time correspond to specific phases of the dust nanoparticle growth. Structural and optical properties of the deposited nanostructured films are described in details. These nanocrystalline Si thin films seem to be promising candidates for all-Si tandem solar cell applications.

Nychyporuk, T.; Zakharko, Yu.; Lysenko, V.; Lemiti, M. [Lyon Institut of Nanotechnologies (INL), CNRS UMR-5270, University of Lyon, INSA de Lyon, 7 avenue Jean Capelle, Bat. Blaise Pascal, 69621 Villeurbanne Cedex (France)

2009-08-24

419

Photolithography I: Thin Film Deposition and Mask Design  

NSDL National Science Digital Library

In this lab, students design, fabricate and test four Al resistors using some of the techniques that are employed to make integrated circuits. First, students will evaporate a thin film of aluminum on a Si wafer. Then, they will use photolithographic techniques to pattern the film and etch away unwanted parts, leaving only your resistors. Students will complete the Al thin film deposition and mask design parts of the process. For the second part of this laboratory activity, click here.

Buhrman, Robert A.; Huang, Kevin; Plisch, Monica; Shull, Alison

2008-10-16

420

Thin film adhesion by nanoindentation-induced superlayers. Final report  

SciTech Connect

This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

Gerberich, William W.; Volinsky, A.A.

2001-06-01

421

Bulge Testing Transparent Thin Films with Moiré Deflectometry  

Microsoft Academic Search

The problem that is addressed here is the measurement of the mechanical properties of very thin, transparent films using bulge\\u000a tests. All existing techniques make use of reflection from the film surface, but they can be difficult or impossible to apply\\u000a to very thin, transparent films. Consequently, a novel approach based on the formation of a lens structure and using

D. Xu; K. M. Liechti

2010-01-01

422

Thin-film technology for HTSC Josephson devices  

Microsoft Academic Search

An overview is given on different thin film preparation methods to produce YBa2Cu3O7-? thin film Josephson devices on various substrates. Beside laser deposition and ion beam etching techniques the use of inhibit technologies for patterning is discussed for the preparation of large area superconducting structures. For the deposition of large area YBa2Cu3O7-? films a heater and dry etching concept is

P. Seidel; F. Schmidl; H. Wald; M. Mans; K. Peiselt; U. Baldeweg; M. Beck; S. Biering; C. Becker; J. Uhlig; V. Groszlige

2005-01-01

423

The US DOE\\/NREL polycrystalline thin film photovoltaics project  

Microsoft Academic Search

Progress in polycrystalline thin films facilitated by the US Department of Energy\\/National Renewable Energy Laboratory (DOE\\/NREL) program has included: accelerated growth of the US industrial infrastructure supporting CuInSe2 (CIS), CdTe, and Si-film; achievement of a record thin-film CIS power module (4 ft2) aperture area efficiency of 9.7%, verified by NREL; improved aperture area efficiency of 8.1%, verified by NREL for

Kenneth Zweibel; Harin S. Ullal; Richard L. Mitchell; Rommel Noufi

1991-01-01

424

Characterization of an epitaxial-growth diamond thin film  

Microsoft Academic Search

The epitaxial-grown diamond thin film on a natural diamond (111) substrate from a mixture of hydrogen and acetone by hot-filament-assisted CVD is studied. The deposited thin film is characterized by REM, RHEED, SEM, optical microscopy, the Laue method, Raman spectroscopy and X-ray topography. The deposited film is found to be completely epitaxial to the substrate with good crystallinity and a

Z. W. Hu; S. S. Jiang; P. Q. Huang; S. H. Li; Z. M. Zhang; C. Z. Ge; X. N. Zhao; D. Feng

1992-01-01

425

Electrochemical photovoltaic cells CdSe thin film electrodes  

Microsoft Academic Search

Progress on developing stable, thin-film CdSe electrodes with sunlight conversion efficiency of 10% for use with aqueous polysulfide electrolytes in frontwall and backwall illuminated EPCs is reported. The main effort was directed towards establishing the relationships among thin-film processing, resultant electronic properties and I-V performance in order to produce electrodes with maximum power conversion efficiency. Films were deposited on titanium

M. A. Russak; J. Reichman; J. Decarlo; C. Creter

1980-01-01

426

Thin film coatings for space electrical power system applications  

NASA Technical Reports Server (NTRS)

This paper examines some of the ways in which thin film coatings can play a role in aerospace applications. Space systems discussed include photovoltaic and solar dynamic electric power generation systems, including applications in environmental protection, thermal energy storage, and radiator emittance enhancement. Potential applications of diamondlike films to both atmospheric and space based systems are examined. Also, potential uses of thin films of the recently discovered high-temperature superconductive materials are discussed.

Gulino, Daniel A.

1988-01-01

427

Characterization of Nickel Oxide Thin Film --- DC Reactive Magnetron Sputtering  

Microsoft Academic Search

Nickel oxide (NiO) thin films were deposited on glass substrates by reactive direct current (DC) magnetron sputtering of a Ni target in an Ar\\/O2 mixture. The effect of thickness (0.2 mum, 0.4 mum and 1 mum) on the structural and surface morphological properties of NiO thin films was investigated. These films were characterized by X-ray diffraction (XRD), Fourier transform infrared

K. Ashok

2011-01-01

428

Transferable and flexible thin film devices for engineering applications  

NASA Astrophysics Data System (ADS)

Thin film devices can be of significance for manufacturing, energy conversion systems, solid state electronics, wireless applications, etc. However, these thin film sensors/devices are normally fabricated on rigid silicon substrates, thus neither flexible nor transferrable for engineering applications. This paper reports an innovative approach to transfer polyimide (PI) embedded thin film devices, which were fabricated on glass, to thin metal foils. Thin film thermocouples (TFTCs) were fabricated on a thin PI film, which was spin coated and cured on a glass substrate. Another layer of PI film was then spin coated again on TFTC/PI and cured to obtain the embedded TFTCs. Assisted by oxygen plasma surface coarsening of the PI film on the glass substrate, the PI embedded TFTC was successfully transferred from the glass substrate to a flexible copper foil. To demonstrate the functionality of the flexible embedded thin film sensors, they were transferred to the sonotrode tip of an ultrasonic metal welding machine for in situ process monitoring. The dynamic temperatures near the sonotrode tip were effectively measured under various ultrasonic vibration amplitudes. This technique of transferring polymer embedded electronic devices onto metal foils yield great potentials for numerous engineering applications.

Mutyala, Madhu Santosh K.; Zhou, Jingzhou; Li, Xiaochun

2014-05-01

429

Superconductor films with improved flux pinning and reduced AC losses  

SciTech Connect

The present invention relates to a method for producing a defect-containing superconducting film, the method comprising (a) depositing a phase-separable layer epitaxially onto a biaxially-textured substrate, wherein the phase-separable layer includes at least two phase-separable components; (b) achieving nanoscale phase separation of the phase-separable layer such that a phase-separated layer including at least two phase-separated components is produced; and (c) depositing a superconducting film epitaxially onto said phase-separated components of the phase-separated layer such that nanoscale features of the phase-separated layer are propagated into the superconducting film.

Goyal, Amit (Knoxville, TN)

2011-04-05

430

Investigations on solution derived aluminium doped zinc oxide thin films  

Microsoft Academic Search

Aluminium (Al) doped transparent zinc oxide thin films have been successfully grown on sapphire (0001) substrates by an economical chemical solution deposition technique. These films were characterized in terms of their structural, optical, and electrical properties. Detailed XPS analysis of the O1s core level spectra has been carried out for the ZnO films annealed at different temperatures. Lower binding energy

S. B Majumder; M Jain; P. S Dobal; R. S Katiyar

2003-01-01

431

Microstructural development of thin films grown by pulsed laser deposition  

Microsoft Academic Search

Pulsed laser deposition (PLD) of thin films involves conditions that differ substantially from those of other vapor deposition techniques and that may be expected to influence film nucleation and growth mechanisms. In order to study the effect of these conditions on these mechanisms, a series of films was deposited using discrete numbers of laser pulses ranging from 1 to 3000.

C. M. Cotell; J. S. Horwitz; J. A. Sprague; R. C. Y. Auyeung; P. D'Antonio; J. Konnert

1995-01-01

432

Chemical Solution Routes to Single-Crystal Thin Films  

Microsoft Academic Search

Epitaxial thin films of inorganic single crystals can be grown on single-crystal substrates with a variety of different solution chemistries. This review emphasizes chemical solution deposition, in which a solution is used to deposit a layer of precursor molecules that decompose to low-density, polycrystalline films during heating. Ways to control film cracking during deposition and heat treatment and why many

F. F. Lange

1996-01-01

433

Thin-film cryogenic resistors from aluminium alloys  

NASA Astrophysics Data System (ADS)

The temperature dependence of the resistances of thin films sputtered from three commercially available aluminium alloys (5052, 5086, 5456) has been measured in the temperature range 1.5-4.2 K. The 5052-alloy films had a positive temperature coefficient of resistance (TCR) throughout this temperature range, whereas films of the other two alloys had a negative TCR.

Tadros, N. N.; Holdeman, L. B.

434

Strong photoluminescence of nanostructured crystalline tungsten oxide thin films  

Microsoft Academic Search

Strong photoluminescence (PL) is observed in nanostructured crystalline tungsten oxide thin films that are prepared by thermal evaporation. Two kinds of films are investigated-one made of nanoparticles and another of nanowires. At room temperature, strong PL emissions at ultraviolet-visible and blue regions are found in both of the films. Compared with the complete absence of emission of bulk phase tungsten

M. Feng; A. L. Pan; H. R. Zhang; Z. A. Li; F. Liu; H. W. Liu; D. X. Shi; B. S. Zou; H. J. Gao

2005-01-01

435

NOTES ON BLOWUP AND LONG WAVE UNSTABLE THIN FILM EQUATIONS  

E-print Network

if the liquid film is uniform in the y direction. We refer to [16], [17] for reviews of the physicalNOTES ON BLOWUP AND LONG WAVE UNSTABLE THIN FILM EQUATIONS M. C. PUGH 1. Introduction We provide film of viscous liquid spreading on a flat solid surface. The air/liquid interface is at height z = u

Pugh, Mary

436

Nanoindentation of copper thin films on silicon substrates  

Microsoft Academic Search

The authors present here experimental results on the nano-indentation of polycrystalline Cu thin films, of three different thicknesses but with approximately the same grain size and texture, on Si substrates. Care was taken to ensure that the indentation response was solely that of the film, with the deformation field of indentation confined fully within the film thickness, and that the

S. Suresh; T.-G. Nieh; B. W. Choi

1999-01-01

437

Analysis of process peculiarities of thin film disalination plants  

Microsoft Academic Search

In this article a large complex of researches on hydrodynamics and heat transfer is carried out on a current of thin film in up flow, down flow and horizontal-tube falling film desalination plants. Based on the results of observation of the mode of movement of a film on such heating surfaces and steam formation, explanations of physical features of hydrodynamics

V. N. Slesarenko

2005-01-01

438

Characterizations of evaporated ?-Si thin films for MEMS application  

NASA Astrophysics Data System (ADS)

Amorphous silicon (?-Si) thin films are widely used as electrical, optical and mechanical materials mainly synthesized by chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition (PECVD) and low pressure chemical vapor deposition. However, the physical vapor deposition ways which are seldom studied may demonstrate a proper choice for the deposition of ?-Si thin films as the structural material for micro-electromechanical systems application. One of the CVD methods of e-beam thermal evaporation was used for the deposition of ?-Si thin films in this study. All samples of deposited ?-Si thin films had smooth surface with the root mean square surface roughness less than 1.6 nm. The ?-Si film with a relatively low stress of about 250 MPa was obtained with a film thickness of 500 nm at a deposition rate of 4.7-6.1 Å/s. The film thickness variation of ?-Si deposited on a 4 inch white glass had a 0.78 % uniformity. The 150-nm-thick ?-Si film showed a good conformality on the patterned 500-nm-thick Mo film and it had a leak current density of 2.8 × 10-3 A/cm2 under a 5 V bias voltage. The film's Young's modulus and hardness were extracted by a nano-indenter with values of 71.6 and 7.9 GPa, respectively. Characteristics of evaporated ?-Si films and PECVD ?-Si:H films were also compared.

Jiao, X. Q.; Zhang, R.; Yang, J.; Zhong, H.; Shi, Y.; Chen, X. Y.; Shi, J.

2014-08-01

439

Free-grown polypyrrole thin films as aroma sensors  

Microsoft Academic Search

We describe the use of free-grown thin polypyrrole films as fast response sensors of volatile compounds. Using a variety of dopants, the polymeric films were prepared directly on conducting glass substrates. Ultraviolet-visible and near infrared regions absorbance measurements were used to investigate the deposition process and the doping level of the films. We identify the polymerization time as the fundamental

J. E. G de Souza; F. L dos Santos; B. B Neto; C. G dos Santos; M. V. B dos Santos; C. P de Melo

2003-01-01

440

Texture development in Ti–Si–N nanocomposite thin films  

Microsoft Academic Search

Nanocomposite thin films of titanium silicon nitride were deposited by sputtering on R-plane sapphire substrates. The effects of silicon addition and negative substrate bias on the texture development of the films were studied systematically by varying the bias voltage in the range ?20 to ?200V. The accompanying changes in the microstructure and growth morphology of the phases in these films

R. Chandra; Davinder Kaur; Amit Kumar Chawla; N. Phinichka; Z. H. Barber

2006-01-01

441

Tilt grain boundaries in YBa sub 2 Cu sub 3 O sub 7-x thin films  

SciTech Connect

Grain boundaries in YBa{sub 2}Cu{sub 3}O{sub 7-x} superconductor thin films grown on (001) MgO by metal-organic chemical vapor deposition (MOCVD) have been characterized using transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). It was found that the YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films were highly textured with the c axes, or (001) orientation, nearly parallel between grains and perpendicular to the MgO substrate. A majority of the grain boundaries are low-angle boundaries with a tilt angle, {theta}, less than 15{degree}. The low-angle boundaries appear to be strongly faceted on an atomic scale in such a way that the boundary planes tend to be parallel to the (100), (010), or (110) lattice planes in one of the adjacent grains. Almost all of the lattice planes, except for a number of distorted regions along the boundaries, are continuous across the boundaries from one grain to another, accommodating the misorientation with a slight bending of the lattice planes. The small-angle boundaries are shown to consist of arrays of dislocations. A domain structure, formed by the interchange of a and b axes has been observed in large grains. The domain boundaries are strongly faceted with the (100) and (010) lattice planes parallel to the boundaries. These observations on the atomic structure of boundaries, are used to discuss the effect of grain boundaries on superconductor properties in YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films. 15 refs., 9 figs.

Gao, Y.; Bai, G.; Chang, H.L.M.; Merkle, K.L.; Lam, D.J.

1990-07-01

442

Stabilization of the dissipation-free current transport in inhomogeneous MgB2 thin films  

NASA Astrophysics Data System (ADS)

In type-II superconductors at T = 0 the critical current density is determined by the pinning of flux lines. Considering an arbitrarily shaped energy landscape the pinning force at each pinning site is given by the derivative of the flux line energy with respect to the considered direction. At finite temperatures, in addition, thermal activation can lead to a depinning of flux lines. The governing property in this case is the depth of the corresponding pinning potential, i.e. the pinning energy. We show a detailed analysis of both pinning forces and pinning energies of MgB2 films with inhomogeneous microstructure. We show that a pronounced increase of the pinning energy is responsible for the significantly enhanced stability of the dissipation-free current transport in thin inhomogeneous MgB2 films. This is found even if the corresponding pinning forces are small.

Treiber, S.; Stahl, C.; Schütz, G.; Soltan, S.; Albrecht, J.

2014-11-01

443

The Curie temperature of thin ferromagnetic films.  

PubMed

The thickness-dependent Curie temperature T(c)(d) of thin ferromagnetic films is calculated within the molecular field approximation ('Weiss mean field') of the Heisenberg model. Two higher mean field theories are applied to obtain a quantitative improvement of the results: the Oguchi cluster method and the 'constant coupling approximation' (CCA). Analytical expressions are derived from difference equations or eigenvalue problems with an unknown parameter which can be solved numerically. Explicit expressions for T(c)(d) can be given if the interaction is restricted to next neighbour monolayers only, for any value of the spin S within the Weiss mean field and for S = 1/2 within the CCA. Effects of an enhanced interaction within the surface layers are briefly investigated. Calculated values of T(c)(d) for EuO are presented within the three models. PMID:21832358

Rausch, Roman; Nolting, Wolfgang

2009-09-16

444

PZT thin film actuated elastic fin micromotor.  

PubMed

A piezoelectric elastic fin micromotor based on a PbZr(0.53 )Ti(0.47)O(3) thin film driving a micromachined silicon membrane was fabricated and studied. The stator was characterized by interferometry, and a laser set-up was used to measure the angular velocity and acceleration of the motor. The torque, the output power, and the efficiency of the device were extracted from these measurements. Values up to 1020 rpm and 0.94 microNm were observed for the velocity and the torque, respectively, which would be sufficient for a wristwatch application. The present version exhibited an efficiency of 0.17%, which could theoretically be increased to 4.8% PMID:18244276

Dubois, M A; Muralt, P

1998-01-01

445

Slip effects in polymer thin films  

E-print Network

Probing the fluid dynamics of thin films is an excellent tool to study the solid/liquid boundary condition. There is no need for external stimulation or pumping of the liquid due to the fact that the dewetting process, an internal mechanism, acts as a driving force for liquid flow. Viscous dissipation within the liquid and slippage balance interfacial forces. Thereby, friction at the solid/liquid interface plays a key role towards the flow dynamics of the liquid. Probing the temporal and spatial evolution of growing holes or retracting straight fronts gives, in combination with theoretical models, information of the liquid flow field and especially the boundary condition at the interface. We review the basic models and experimental results obtained during the last years with exclusive regard to polymers as ideal model liquids for fluid flow. Moreover, concepts that aim on explaining slippage on the molecular scale are summarized and discussed.

O. Baeumchen; K. Jacobs

2009-09-10

446

Nonlinear optics of astaxanthin thin films  

NASA Astrophysics Data System (ADS)

Carotinoids exhibit large nonlinear optical properties due to their extended (pi) -electron system. Compared to other polyenes which show a broad distribution of conjugation lengths, carotinoids exhibit a well defined molecular structure, i.e. a well defined conjugation length. Therefore the carotinoid molecules can serve as model compounds to study the relationship between structure and nonlinear optical properties. In this paper the synthesis of four astaxanthins with C-numbers ranging from 30 to 60, their preparation into thin films, wavelength dispersive Third Harmonic Generation (THG) measurements and some molecular modelling calculations will be presented. Resonant (chi) (3) values reach 1.2(DOT)10-10 esu for C60 astaxanthin. In the nonresonant regime a figure of merit (chi) (3)/(alpha) of several 10-13 esu-cm is demonstrated.

Esser, A.; Fisch, Herbert; Haas, Karl-Heinz; Haedicke, E.; Paust, J.; Schrof, Wolfgang; Ticktin, Anton

1993-02-01

447

Structure of Thin-Film Lithium Microbatteries  

NASA Technical Reports Server (NTRS)

A process for making thin-film batteries including the steps of cleaning a glass or silicon substrate having an amorphous oxide layer several microns thick; defining with a mask the layer shape when depositing cobalt as an adhesion layer and platinum as a current collector; using the same mask as the preceding step to sputter a layer of LiC(0)O2, on the structure while rocking it back and forth; heating the substrate to 300 C. for 30 minutes; sputtering with a new mask that defines the necessary electrolyte area; evaporating lithium metal anodes using an appropriate shadow mask; and, packaging the cell in a dry-room environment by applying a continuous bead of epoxy around the active cell areas and resting a glass slide over the top thereof. The batteries produced by the above process are disclosed.

Whitacre, Jay F. (Inventor); Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor)

2003-01-01

448

Magnesium diboride thin films and devices  

Microsoft Academic Search

Magnesium diboride (MgB2) is a binary compound superconductor with a superconducting transition temperature Tc of ˜40 K. MgB2 has two conduction bands: a two-dimensional sigma band and a three-dimensional pi band with weak interband scattering. The two gap superconductivity in MgB2 gives rise to many interesting physical properties not possible in other superconductors. The relatively high Tc combined with phonon

Yi Cui

2007-01-01

449

Broadly tunable thin-film intereference coatings: active thin films for telecom applications  

NASA Astrophysics Data System (ADS)

Thin film interference coatings (TFIC) are the most widely used optical technology for telecom filtering, but until recently no tunable versions have been known except for mechanically rotated filters. We describe a new approach to broadly tunable TFIC components based on the thermo-optic properties of semiconductor thin films with large thermo-optic coefficients 3.6X10[-4]/K. The technology is based on amorphous silicon thin films deposited by plasma-enhanced chemical vapor deposition (PECVD), a process adapted for telecom applications from its origins in the flat-panel display and solar cell industries. Unlike MEMS devices, tunable TFIC can be designed as sophisticated multi-cavity, multi-layer optical designs. Applications include flat-top passband filters for add-drop multiplexing, tunable dispersion compensators, tunable gain equalizers and variable optical attenuators. Extremely compact tunable devices may be integrated into modules such as optical channel monitors, tunable lasers, gain-equalized amplifiers, and tunable detectors.

Domash, Lawrence H.; Ma, Eugene Y.; Lourie, Mark T.; Sharfin, Wayne F.; Wagner, Matthias

2003-06-01

450

Growth of epitaxial ZnO thin film by oxidation of epitaxial ZnS thin film on Si(111)  

Microsoft Academic Search

The growth of epitaxial ZnO thin film on Si substrate by the oxidation of epitaxial ZnS film is a novel method and we are reporting this first time. The merits of the use of Si substrate are to make driving voltage in LED lower and less expensive than sapphire substrate. In this study, the epitaxial ZnO thin film could be

A. Miyake; H. Kominami; T. Aoki; H. Tatsuoka; H. Kuwabara; Y. Nkanishi; Y. Hatanaka

2001-01-01

451

Growth of epitaxial ZnO thin film by oxidation of epitaxial ZnS thin films on Si(111)  

Microsoft Academic Search

The growth of epitaxial ZnO thin film on Si substrate by the oxidation of epitaxial ZnS film is a novel method and we are reporting this first time. The merits of the use of Si substrate are to make driving voltage in LED lower and less expensive than sapphire substrate. In this study, the epitaxial ZnO thin film could be

A. Miyake; H. Kominami; T. Aoki; H. Tatsuoka; H. Kuwabara; Y. Nkanishi; Y. Hatanaka

2001-01-01

452

Niobium Nitride Thin Films and Multilayers for Superconducting Radio Frequency Cavities  

NASA Astrophysics Data System (ADS)

Niobium nitride in thin film form has been considered for a number of applications including multi-layered coatings onto superconducting radio frequency cavities which have been proposed to overcome the fundamental accelerating gradient limit of ˜50 MV/m in niobium based accelerators [1]. In order to fulfill the latter application, the selected superconductor's thermodynamic critical field, HC, must be larger than that of niobium and separated from the Nb surface by an insulating layer in order to shield the Nb cavity from field penetration and thus allow higher field gradients. Thus, for the successful implementation of such multilayered stack it is important to consider not just the materials inherent properties but also how these properties may be affected in thin film geometry and also by the specific deposition techniques used. Here, we show the results of our correlated study of structure and superconducting properties in niobium nitride thin films and discuss the shielding exhibited in NbN/MgO/Nb multilayer samples beyond the lower critical field of Nb for the first time.[4pt] [1] A. Gurevich, Appl. Phys. Lett., 88, 012511 (2006).

Roach, William; Beringer, Douglas; Li, Zhaozhu; Clavero, Cesar; Lukaszew, Rosa

2013-03-01

453

Effects of heat treatment process on thin film alloy resistance and its stability  

Microsoft Academic Search

Alloy thin film for advanced pressure sensors was manufactured by means of ion-beam sputtering SiO2 insulation film and NiCr thin film on the 17-4PH stainless steel elastic substrate. The thin film resistance was respectively\\u000a heat-treated by four processes. The effects on stability of thin film alloy resistance were investigated, and paramaters of\\u000a heat treatment that make thin film resistance stable

Ji-cheng Zhou; Yin-qiao Peng

2003-01-01

454

Straining Graphene Using Thin Film Shrinkage Methods  

PubMed Central

Theoretical works suggest the possibility and usefulness of strain engineering of graphene by predicting remarkable properties, such as Dirac cone merging, bandgap opening and pseudo magnetic field generation. However, most of these predictions have not yet been confirmed because it is experimentally difficult to control the magnitude and type (e.g., uniaxial, biaxial, and so forth) of strain in graphene devices. Here we report two novel methods to apply strain without bending the substrate. We employ thin films of evaporated metal and organic insulator deposited on graphene, which shrink after electron beam irradiation or heat application. These methods make it possible to apply both biaxial strain and in-plane isotropic compressive strain in a well-controlled manner. Raman spectroscopy measurements show a clear splitting of the degenerate states of the G-band in the case of biaxial strain, and G-band blue shift without splitting in the case of in-plane isotropic compressive strain. In the case of biaxial strain application, we find out the ratio of the strain component perpendicular to the stretching direction is at least three times larger than what was previously observed, indicating that shrinkage of the metal or organic insulator deposited on graphene induces both tensile and compressive strain in this atomically thin material. Our studies present for the first time a viable way to apply strain to graphene without the need to bend the substrate. PMID:24490629

2014-01-01

455

Integration of thin film decoupling capacitors  

SciTech Connect

Thin film decoupling capacitors consisting of submicron thick, sol-gel Pb(Zr,Ti)O{sub 3} layers between Pt electrodes on a Si substrate have recently been developed. Because the capacitor structure needs to be only {approximately}3 {mu}m thick, these devices offer advantages such as decreased package volume and ability to integrate so that interconnect inductance is decreased, which allows faster IC processing rates. To fully utilize these devices, techniques of integrating them onto packages such as multi-chip modules and printed wiring boards or onto IC dies must be developed. The results of our efforts at developing integration processes for these capacitors are described here. Specifically, we have demonstrated a process for printing solder on the devices at the Si wafer level and reflowing it to form bumps and have developed a process for fabricating the devices on thin (25 to 75 {mu}m) substrates to facilitate integration onto ICs and printed wiring boards. Finally, we assessed the feasibility of fabricating the devices on rough surfaces to determine whether it would be possible to fabricate these capacitors directly on multi-layer ceramic substrates.

Garino, T.; Dimos, D.; Lockwood, S.

1994-10-01

456

Thin film thermocouples for high temperature measurement on ceramic materials  

NASA Technical Reports Server (NTRS)

Thin film thermocouples have been developed for use on metal parts in jet engines to 1000 C. However, advanced propulsion systems are being developed that will use ceramic materials and reach higher temperatures. The purpose of this work is to develop thin film thermocouples for use on ceramic materials. The thin film thermocouples are Pt13Rh/Pt fabricated by the sputtering process. Lead wires are attached using the parallel-gap welding process. The ceramic materials are silicon nitride, silicon carbide, aluminum oxide, and mullite. Both steady state and thermal cycling furnace tests were performed in the temperature range to 1500 C. High-heating-rate tests were performed in an arc lamp heat-flux-calibration facility. The fabrication of the thin film thermocouples is described. The thin film thermocouple output was compared to a reference wire thermocouple. Drift of the thin film thermocouples was determined, and causes of drift are discussed. The results of high-heating-rate tests up to 2500 C/sec are presented. The stability of the ceramic materials is examined. It is concluded that Pt13Rh/Pt thin film thermocouples are capable of meeting lifetime goals of 50 hours or more up to temperatures of 1500 C depending on the stability of the particular ceramic substrate.

Holanda, Raymond

1992-01-01

457

Method for making surfactant-templated thin films  

DOEpatents

An evaporation-induced self-assembly method to prepare a porous, surfactant-templated, thin film by mixing a silica sol, a solvent, a surfactant, and an interstitial compound, evaporating a portion of the solvent to form a liquid, crystalline thin film mesophase material, and then removal of the surfactant template. Coating onto a substrate produces a thin film with the interstitial compound either covalently bonded to the internal surfaces of the ordered or disordered mesostructure framework or physically entrapped within the ordered or disordered mesostructured framework. Particles can be formed by aerosol processing or spray drying rather than coating onto a substrate. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.

Brinker, C. Jeffrey (Albuquerque, NM); Lu, Yunfeng (New Orleans, LA); Fan, Hong You (Albuquerque, NM)

2010-08-31

458

Method for making surfactant-templated thin films  

DOEpatents

An evaporation-induced self-assembly method to prepare a porous, surfactant-templated, thin film by mixing a silica sol, a solvent, a surfactant, and an interstitial compound, evaporating a portion of the solvent to form a liquid, crystalline thin film mesophase material, and then removal of the surfactant template. Coating onto a substrate produces a thin film with the interstitial compound either covalently bonded to the internal surfaces of the ordered or disordered mesostructure framework or physically entrapped within the ordered or disordered mesostructured framework. Particles can be formed by aerosol processing or spray drying rather than coating onto a substrate. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.

Brinker, C. Jeffrey (Albuquerque, NM); Lu, Yunfeng (San Jose, CA); Fan, Hongyou (Albuquerque, NM)

2002-01-01

459

Optical and Structural Properties of Ultra-thin Gold Films  

E-print Network

Realizing laterally continuous ultra-thin gold films on transparent substrates is a challenge of significant technological importance. In the present work, formation of ultra-thin gold films on fused silica is studied, demonstrating how suppression of island formation and reduction of plasmonic absorption can be achieved by treating substrates with (3-mercaptopropyl) trimethoxysilane prior to deposition. Void-free fi lms with deposition thickness as low as 5.4 nm are realized and remain structurally stable at room temperature. Based on detailed structural analysis of the fi lms by specular and diffuse X-ray reflectivity measurements, it is shown that optical transmission properties of continuous ultra-thin films can be accounted for using the bulk dielectric function of gold. However, it is important to take into account the non-abrupt transition zone between the metal and the surrounding dielectrics, which extends through several lattice constants for the laterally continuous ultra-thin films (film thickness...

Kossoy, Anna; Simakov, Denis; Leosson, Kristjan; Kéna-Cohen, Stéphane; Maier, Stefan A

2014-01-01

460

Thin-film Sensors for Space Propulsion Technology  

NASA Technical Reports Server (NTRS)

SSME components such as the turbine blades of the high pressure fuel turbopump are subjected to rapid and extreme thermal transients that contribute to blade cracking and subsequent failure. The objective was to develop thin film sensors for SSME components. The technology established for aircraft gas turbine engines was adopted to the materials and environment encountered in the SSME. Specific goals are to expand the existing thin film sensor technology, to continue developing improved sensor processing techniques, and to test the durability of aircraft gas turbine engine technology in the SSME environment. A thin film sensor laboratory is being installed in a refurbished clean room, and new sputtering and photoresist exposure equipment is being acquired. Existing thin film thermocouple technology in an SSME environment are being tested. Various coatings and their insulating films are being investigated for use in sensor development.

Kim, W. S.; Englund, D. R.

1985-01-01